Industrial vehicle

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to an industrial vehicle equipped with a transmission.

【0002】

[Conventional technology]

The transmission system for industrial vehicles can be broadly divided into two types: a torque converter transmission system and a transmission connected to a hydraulic drive motor (hereinafter abbreviated as HST motor) driven by a hydrostatic pump (hereinafter abbreviated as HST pump). There is a method of shifting the speed. Hereinafter, the transmission method of this HST motor will be described.

【0003】

Conventionally, in an industrial vehicle equipped with an HST pump directly connected to an engine and an HST motor driven by this pump, and a transmission connected to the HST motor to drive an axle, the engine speed is determined by the accelerator pedal. Control the rotation of the HST motor by controlling the operation to control the rotation of the HST motor, or by controlling the angle of the swash plate of the HST pump that sets the amount of hydraulic oil discharged from the HST pump to the HST motor. In addition, the speed of the vehicle is adjusted by shifting the speed with the transmission.

【0004】

The main configuration of the conventional industrial vehicle will be described in detail with reference to FIG.

【0005】

In FIG. 5, reference numeral 1 denotes an engine whose rotation speed is controlled by operating the accelerator pedal 2. The HST pump 3 and the main pump 4 that supplies oil to the main circuits of cargo handling devices such as booms and buckets are supplied to the engine 1. And the charging pump 5 is directly connected.

【0006】

As described above, the HST pump 3 is a pump in which the swash plate 6 changes its scroll (not shown) and the amount of hydraulic oil discharged to the HST motor 7 changes, and the angle setting servo cylinder 9 changes the swash plate. By controlling the angle setting of 6, the rotation speed of the HST motor 7 is controlled. Further, the charging pump 5 supplies hydraulic oil to the HST control valve 10 of the swash plate 6.

【0007】

The HST control valve 10 generates a pressure difference due to the hydraulic oil from the charging pump 5 on both supports of the servo cylinder 9 according to the forward, neutral, and reverse selection operations of the direction change lever. When the inching solenoid valve 11 of the HST control valve 10 is driven by the inching detection pressure sensor 13 that detects the operation of the brake pedal 12, the control pressure on the servo cylinder 9 is adjusted, which is related to the rotation speed of the engine 1. The angle of the swash plate 6 is reduced and the vehicle slows down or stops.

【0008】

The operation according to the above configuration will be described.

【0009】

First, when the engine 1 rotates, the hydraulic oil discharged from the charging pump 5 is supplied to the HST control valve 10, and when the direction change lever is operated to the forward or reverse position, the pressure difference is applied to both ports of the servo cylinder 9. (This pressure difference becomes the control pressure of the servo cylinder 9). Next, when the accelerator pedal 2 is depressed, the rotation speed of the engine 1 increases, the discharge amount of the hydraulic oil of the charging pump 5 increases, and the control pressure increases. Then, when the control pressure reaches the force for operating the swash plate 6, the swash plate 6 of the HST pump 3 rotates, hydraulic oil is discharged from the HST pump 3 to the HST motor 7, and the vehicle moves forward or backward. At this time, the hydraulic oil discharged from the main pump 4 is supplied to the main circuit of the cargo handling device.

【0010】

Further, when the brake pedal 12 is operated, the inching solenoid valve 11 is driven via the inching detection pressure sensor 13, the control pressure to the servo cylinder 9 is adjusted, and the swash plate 6 is adjusted regardless of the rotation speed of the engine 1. The angle of the vehicle decreases and the vehicle slows down or stops. Further, when a load is applied to the vehicle, the force for returning to neutrality increases on the swash plate 6 of the HST pump 3, the angle of the swash plate 6 decreases, and the speed of the vehicle automatically slows down.

【0011】

Further, as shown in FIG. 5, one shaft of the transmission 15 is connected to the shaft of the HST motor 7, the axle 16 is connected to the other shaft of the transmission 21, and the parking brake 17 and the parking brake 17 are regularly used on the axle 16. Brake (disc brake) 18 is installed. The parking brake 17 is driven by the parking brake knob 19, and the regular brake 18 is driven by the operation of the brake pedal 12 via the master cylinder 20. Further, in the transmission 15, the speed stage is selected and the speed is changed by operating the change lever for the transmission. Further, in FIG. 5, reference numeral 21 denotes a traveling speed detector (an example of speed detecting means) that detects the speed of the vehicle by detecting the rotation speed (vehicle speed frequency) of the axle 16.

【0012】

[Problems to be Solved by the Invention]

However, in such industrial vehicles, since cargo handling work and running are repeated, shifting operations are frequently performed by the transmission change lever, and in response to various situations such as differences in conditions due to load and no load and slopes. Since the gear shifting operation must be performed, there is a problem that the workability is poor and the burden on the worker is heavy.

【0013】

Therefore, an object of the present invention is to provide an industrial vehicle that can easily cope with various situations and improve workability.

【0014】

[Means for solving problems]

In order to achieve the above-mentioned object, the invention according to claim 1 of the present invention is an industrial vehicle including a transmission, which comprises a speed detecting means for detecting the speed of the vehicle and a first gear of the transmission. 1st speed fixed mode that uses only the 1st speed fixed mode, 2nd speed fixed mode that uses only the 2nd speed gear of the transmission, economy mode that automatically shifts using the high speed gear of the transmission, and all gears of the transmission A selection means for selecting a power mode for automatic shifting by using and a control means for controlling the shifting of the transmission based on the speed of the vehicle detected by the speed detection means and the mode selected by the selection means. It is characterized by being prepared.

【0015】

According to the above configuration, there is a "1st gear fixed mode" that uses 1st gear, which is effective when working in narrow places such as onboard work, on slopes, or when strong engine braking is required, or there is a maximum speed limit. Also, since there are no shift points and the brake points do not overlap and shift shocks do not occur, "2-speed fixed mode" that uses the optimum 2-speed gear when carrying unstable or luggage or precision luggage, or "Power mode" that automatically shifts using all gears, which is used when the load is heavy or when driving at low speed is required when driving automatically, or when driving automatically, there is less shift shock "Economy mode" is selected, which has excellent acceleration and is expected to improve work efficiency and fuel efficiency, and automatically shifts using high-speed gears. The transmission is based on the selected mode and vehicle speed. Shift is performed. The mode can be selected according to various road surface conditions such as differences in work conditions due to load and no load and slopes, that is, various situations can be easily dealt with. Further, in these modes, the worker shifts gears. Since it is not necessary to perform the above, workability can be improved and the burden on the worker can be reduced.

【0016】

The invention according to claim 2 of the present invention is the invention according to claim 1, wherein the second-speed gear and the third-speed gear of the transmission are used in the economy mode, and the control means is the economy. When the mode is selected, the shift point for switching between the second gear and the third gear is set to a speed lower than the shift point in the power mode.

【0017】

According to the above configuration, the acceleration property is further improved and the fuel consumption is improved.

【0018】

The invention according to claim 3 of the present invention is the invention according to claim 1 or 2, wherein the control means is fixed to the 1st speed by the selection means while operating from the economy mode or the power mode. When mode or 2-speed fixed mode is selected, the vehicle speed is reduced to the speed range in which the 1-speed gear or 2-speed gear is used, and then the selected 1-speed fixed mode or 2-speed fixed mode is entered. It is characterized by that.

【0019】

According to the above configuration, the speed is reduced to a safe speed and the gear is switched to the selected fixed mode gear. Therefore, the shock due to shifting is eliminated, and the load collapse is prevented.

【0020】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same components as those shown in FIG. 5 of the conventional example are designated by the same reference numerals, and the description thereof will be omitted.

【0021】

FIG. 1 is a main part control configuration diagram of an industrial vehicle showing an embodiment of the present invention.

【0022】

In FIG. 1, reference numeral 31 denotes a control device (an example of a control means), which is provided in the driver's seat with a speed mode signal selected by operating a shift hold select switch (an example of a selection means) 32 provided in the driver's seat. The speed mode signal at the time of automatic transmission selected by the operation of the auto mission mode select switch (example of selection means) 33 and the vehicle speed signal of the traveling speed detector 21 are input, and the first speed and the third speed of the transmission 15 are input. It controls the solenoid valves 34 and 35 for the speed stage clutch and the solenoid valves 11 for inching.

【0023】

When "1st speed fixed mode", "2nd speed fixed mode" and "automatic mode" are selected by the shift hold select switch 32, and "automatic mode" is selected by the automission mode select switch 33. , "Economy mode" and "Power mode" are selected.

【0024】

The hydraulic oil supplied from the charging pump 5 is regulated and supplied from the transmission control valve 37 to the solenoid valves 34 and 35 for each speed stage clutch, and is supplied to the 1st gear 1ST and the 3rd gear 3RD. When neither the 1st gear nor the 3rd gear solenoid valves 34 and 35 of the transmission 15 are selected, the hydraulic oil is supplied to the 2nd gear 2ND and the 2nd gear is selected.

【0025】

Figure 4 shows the relationship between vehicle speed and driving force in each gear. In the above "power mode", the 1st gear, 2nd gear, and 2nd gear are shifted by 8km (speed), the 2nd gear and 3rd gear are shifted by 17km (speed), and the shifting point effectively uses the engine torque. It is set to do. In "economy mode", the 2nd and 3rd gears are changed at 13km (speed), and the shifting point is set earlier than in the power mode.

【0026】

The block diagram of the control device 31 is shown in FIGS. 2 and 3.

【0027】

As shown in Fig. 3, in order to detect the shift point, the traveling speed detector 21 turns on when the vehicle speed is higher than 13 km, turns off when the vehicle speed is lower than 11 km, and excites relay # E23 when it is on. , When the vehicle speed of the traveling speed detector 21 is higher than 8 km, it is turned on, when it is smaller than 6 km, it is turned off, and when it is on, the comparator 42 that excites relay # P12 and the vehicle speed of the traveling speed detector 21 are larger than 17 km. A comparator 43 is provided that turns on when it becomes, turns off when it becomes smaller than 15 km, and excites relay # P23 when it is on.

【0028】

In addition, as shown in Fig. 2, the "1st speed fixed mode" relay # 1S, the "2nd speed fixed mode" relay # 2S, and the "economy mode" correspond to the operation signals of the operation switches 32 and 33. Relay #AE and "Power Mode" relay #AP are provided.

【0029】

Furthermore, when "1st speed fixed mode" is selected, if the vehicle speed of the traveling speed detector 21 is greater than 8km (when relay # 1S is on and relay # P12 is on), or "2nd speed fixed mode" is selected. When selected, a solenoid #LCK that is excited when the vehicle speed of the traveling speed detector 21 is greater than 13 km (when relay # 2S is on and relay # E23 is on) is provided, and when this relay #LCK operates. (When turned on), an operation signal is output to the solenoid valve 11 for inching. Therefore, when shifting to the fixed mode of 1st or 2nd speed, if the speed range of the gears in these modes is exceeded, the solenoid valve 11 for inching is driven, the control pressure to the servo cylinder 9 is adjusted, and the engine 1 The angle of the swash plate 6 is reduced and the rotation speed n of the HST motor 7 is reduced regardless of the rotation speed of the HST motor 7, and the vehicle is decelerated.

【0030】

Furthermore, when "1st speed fixed mode" is selected, if the vehicle speed of the traveling speed detector 21 is less than 8km (when reset # 1S is on and relay # P12 is off), or "2nd speed fixed mode" is selected. When selected, a relay #CHG that is excited when the vehicle speed of the traveling speed detector 21 is less than 13 km (when the relay # 2S is on and the relay # E23 is off) is provided, and the relay # of the "economy mode" is provided. AE and "power mode" relay #AP are reset when this relay #CHG is activated (turned on). 44 and 45 are RS flip-flops.

【0031】

Therefore, the relay #AE and the relay #AP are fixed even when the "1-speed fixed mode" or the "2-speed fixed mode" is selected with the relay #AE and the relay #AP set. It is not reset until it is decelerated to the speed range of the mode gear, and the state is maintained to prevent sudden shift shock.

【0032】

As shown in FIG. 3, for the solenoid valve 34 for the 1st speed speed stage clutch, "1st speed fixed mode" is selected (relay # 1S on) and not "economy mode" (relay #AE off). When not in "power mode" (relay # AP off), or when "power mode" is selected (relay # AP on) and the vehicle speed of the traveling speed detector 21 is less than 8 km (relay # P12 off), the signal is It is output and the solenoid valve 34 for the 1st speed speed stage clutch is excited.

【0033】

When "economy mode" is selected (relay # AE on) and the vehicle speed of the traveling speed detector 21 is greater than 13 km (relay # E23 on), "power" is selected for the solenoid valve 35 for the 3-speed speed stage clutch. When "Mode" is selected (Relay # AP on) and the vehicle speed of the traveling speed detector 21 is greater than 17 km (Relay # P23 on), a signal is output and the solenoid valve 35 for the 3rd speed speed stage clutch is excited. To.

【0034】

The operation of the above configuration will be described.

【0035】

First, when the engine 1 rotates, the hydraulic oil discharged from the charging pump 5 is supplied to the HST control valve 10 and the transmission control valve 37, and when the direction change lever is operated to the forward or reverse position, the pressure difference is servoed. It is applied to both ports of the cylinder 9 (this pressure difference becomes the control pressure of the servo cylinder 9). Driving in "1st speed fixed mode" In this state (the vehicle is stopped), when "1st gear fixed mode" is selected by the shift hold select switch 32, the relay # 1S is excited, and the control device 31 releases the solenoid valve 34 for the 1st gear clutch. Excited, hydraulic oil is supplied to the 1st gear 1ST, and the 1st gear of the transmission 15 is connected.

【0036】

Next, when the accelerator pedal 2 is depressed, the rotation speed of the engine 1 increases, the discharge amount of the hydraulic oil of the charging pump 5 increases, and the control pressure increases. Then, when the control pressure reaches the force for operating the swash plate 6, the swash plate 6 of the HST pump 3 rotates, hydraulic oil is discharged from the HST pump 3 to the HST motor 7, the HST motor 7 is driven, and gear shifting is performed. The axle 16 is driven via the 1st gear of the machine 15, and the vehicle moves forward or backward. At this time, the hydraulic oil discharged from the main pump 4 is supplied to the main circuit.

【0037】

When the brake pedal 12 is operated, the normal brake 18 is driven via the master cylinder 20 and the inching solenoid valve 11 is driven via the inching detection pressure sensor 13, and the control pressure on the servo cylinder 9 is controlled. Is adjusted, the angle of the swash plate 6 decreases regardless of the rotation speed of the engine 1, the rotation speed of the HST motor 7 decreases, and the vehicle slows down or stops. Further, when a load is applied to the vehicle, the force for returning to neutrality increases on the swash plate 6 of the HST pump 3, the angle of the swash plate 6 decreases, and the speed of the vehicle automatically slows down.

【0038】

Thus, in the "1st gear fixed mode", only the 1st gear is used. Although this mode can only run at low speeds, it has a large driving force, so it is effective when working in narrow places such as onboard work, working on slopes, or when strong engine braking is required. Driving in "2-speed fixed mode" When "2nd gear fixed mode" is selected by the shift hold select switch 32, relay # 2S is excited, and when relay # 2S is turned on, the solenoid valves 34 and 35 for the 1st and 3rd gear speed stage clutches are Since both are non-excited, hydraulic oil is supplied to the 2nd gear 2ND of the transmission 15 as shown in FIG. 1, and the 2nd gear is connected. Other operations are the same as in "1st speed fixed mode".

【0039】

Thus, in the "2-speed fixed mode", only the 2-speed gear is used. It is effective for use when there is a maximum speed limit, and since there is no shift point and the brake points do not overlap and shift shock does not occur, it is ideal for carrying unstable or luggage or precision luggage. Driving in "power mode" If the shift hold select switch 32 selects the "automatic mode" and the automission mode select switch 33 selects the "power mode" at this time, the relay #AP is excited. At first, the relays # P12 and # P23 that detect the shift point in the power mode are both off, so the control device 31 excites the solenoid valve 34 for the 1st speed gear clutch, and the hydraulic oil goes to the 1st gear 1ST. It is supplied and the 1st gear of the transmission 15 is connected.

【0040】

Then, when the accelerator pedal 2 is depressed to increase the speed of the vehicle and the relay # P12 operates beyond the shift point of the power mode, the solenoid valves 34 and 35 for the speed stage clutches of the 1st and 3rd speeds are both unexcited. And the 2nd gear is connected. When the speed of the vehicle further increases and the relay # P23 operates beyond the shift point in the power mode, the control device 31 excites the solenoid valve 35 for the 3rd speed speed clutch, and the hydraulic oil is transferred to the 3rd speed gear 3RD. It is supplied and the 3rd gear of the transmission 15 is connected.

【0041】

When the speed is reduced and relay # P23 is turned off, the solenoid valves 34 and 35 for the speed stage clutches of the 1st and 3rd speeds are both de-energized, and the 2nd speed gear is connected. Then, when the speed is further reduced and the relay # P12 is turned off, the control device 31 excites the solenoid valve 34 for the speed stage clutch of the 1st speed, hydraulic oil is supplied to the 1st speed gear 1ST, and the 1st speed of the transmission 15 is used. The gear is connected.

【0042】

In this way, in the "power mode", the 1st gear, the 2nd gear, and the 3rd gear are automatically changed. This "power mode" is effective when the load is heavy and when driving at a low speed is required when driving in an automatic manner.

【0043】

Also, when this "power mode" is selected (relay #AP is on) and "1st speed fixed mode" or "2nd speed fixed mode" is selected by the shift hold select switch 32, these 1st speed or When the speed range of the 2nd speed fixed mode gear is exceeded, the relay #LCK is excited, the solenoid valve 11 for inching is driven, the control pressure to the servo cylinder 9 is adjusted, and it is related to the rotation speed of the engine 1. The angle of the swash plate 6 is reduced, the rotation speed n of the HST motor 7 is reduced, and the vehicle is decelerated. Then, when the speed is reduced to the speed range of the gear of the selected fixed mode, the relay #CHG is excited, the relay #AP is reset, and the mode shifts to the selected fixed mode. Therefore, the shift shock can be prevented and the load can be prevented from collapsing. Driving in "economy mode" If the shift hold select switch 32 selects the "automatic mode" and the automission mode select switch 33 selects the "economy mode" at this time, the relay #AE is excited. Initially, relay # E23, which detects the shift point in economy mode, is off, so the solenoid valves 34 and 35 for the 1st and 3rd gear speed stage clutches are both unexcited, so they operate as shown in Fig. 1. Oil is supplied to the 2nd gear 2ND of the transmission 15 and the 2nd gear is connected.

【0044】

Then, when the accelerator pedal 2 is depressed to increase the speed of the vehicle and the relay # E23 operates beyond the shifting point in the economy mode, the control device 31 excites the solenoid valve 35 for the 3rd speed gear clutch and operates. Oil is supplied to the 3rd gear 3RD, and the 3rd gear of the transmission 15 is connected. When the speed is reduced and the relay # E23 is turned off again, the solenoid valves 34 and 35 for the speed stage clutches of the 1st and 3rd speeds are both de-energized and the 2nd speed gear is connected.

【0045】

In this way, in the "economy mode", the 2nd gear and the 3rd gear are automatically changed. As shown in Fig. 4, shifting of the 2nd and 3rd gears is performed at 13km (speed), and the shifting point is set earlier than the power mode, so the "economy mode" accelerates with less shifting shock. It has excellent properties, and is expected to improve work efficiency and fuel efficiency.

【0046】

Also, when this "economy mode" is selected (relay #AE is on) and "1st speed fixed mode" or "2nd speed fixed mode" is selected by the shift hold select switch 32, these 1st speed or When the speed range of the gear in the 2nd speed fixed mode is exceeded, the solenoid valve 11 for inching is driven, the control pressure to the servo cylinder 9 is adjusted, and the angle of the swash plate 6 is adjusted regardless of the rotation speed of the engine 1. The number of revolutions n of the HST motor 7 is reduced, and the vehicle is decelerated. Then, when the speed is reduced to the speed range of the gear in the fixed mode, the relay #AE is reset and the mode shifts to the selected fixed mode. Therefore, the shift shock can be prevented and the load can be prevented from collapsing.

【0047】

As described above, with the shift hold select switch 32 and the automission mode select switch 33, each mode can be selected according to the difference in work conditions due to load and no load and various road surface conditions such as slopes, that is, various modes. In these modes, it is not necessary for the worker to shift gears, so that the workability can be improved and the burden on the worker can be reduced.

【0048】

Even when the control device 31 fails for some reason, both the speed stage clutch solenoid valves 34 and 35 are de-energized, and the vehicle can be moved by connecting the second gear.

【0049】

In the above embodiment, the rotation speed n of the HST motor 7 is reduced by driving the solenoid valve 11 for inching when the vehicle is decelerated, but the normal brake 18 is operated or the rotation speed of the engine 1 is operated. The rotation speed n of the HST motor 7 can be reduced and decelerated by other methods such as controlling the speed to drop.

【0050】

Further, the means for selecting each mode (shift hold select switch 32 and automission mode select switch 33) is a switch type, but a lever type can also be used. The lever type improves operation efficiency when switching modes frequently.

【0051】

Further, in the above embodiment, the transmission method of the HST motor is described, but the present invention can also be applied to the torque converter transmission method, and the same effect can be expected.

【0052】

[Effect of the invention]

As described above, according to the present invention, it is possible to provide an industrial vehicle that can easily cope with various situations and improve workability.

[Simple explanation of drawings]

[Figure 1]

It is a main part control block diagram of the industrial vehicle which shows the embodiment of this invention.

[Figure 2]

It is a block diagram of the control device of the industrial vehicle.

[Fig. 3]

It is a block diagram of the control device of the industrial vehicle.

[Fig. 4]

It is a characteristic diagram of the vehicle speed and the driving force of each transmission gear of the industrial vehicle.

[Fig. 5]

It is a block diagram of the main part of the conventional industrial vehicle.

[Explanation of symbols]

1 engine 2 Accelerator pedal 3 HST pump (hydrostatic pump) 4 Main pump 5 Charging pump 6 Swash plate 7 HST motor (flood drive motor) 9 Servo cylinder 10 HST control valve 11 Solenoid valve for inching 12 Brake pedal 13 Inching detection pressure sensor 15 transmission 16 axles 17 Parking brake 18 Regular brake 21 Traveling speed detector (speed detecting means) 31 Control device (control means) 32 Shift hold select switch (selection means) 33 Automission mode select switch (selection means) 34,35 Solenoid valve for speed stage clutch 37 Transmission control valve