Lubrication device for a clutch system

The present invention relates to a lubricating device for of a motor vehicle clutch gearbox system.

One area of ​​application is particularly the boxes speed two wet clutches for which it is necessary lubricate both.

Of known coupling devices comprise means for distribution of oil and a lubrication system to dissipate energy heat produced by said clutch system.

Where clutches are used in situations where they produce a lot of thermal energy by friction, for example by starting of the vehicle or the gear changes at high speeds, the lubricating oil flow should be sufficient to evacuate this energy thermal

In addition, this oil must be properly cooled in cooling means consist of a heat exchanger on the one hand only not that it degrades and also for it to dissipate properly the thermal energy produced by the clutches.

However, when clutches produce little energy, in the phases of operation corresponding to the normal rolling of vehicle, for example when passing at low speeds or speeds prospective controlled slip, the lubrication flow must be adapted to lubricate the clutch friction surfaces without generating too much friction torque and penalize the performance of the transmission.

In known clutch systems, the lubrication flow rate is provided by a pressure regulator which ensures a pressure fixed in the lubricating circuit and therefore a fixed rate. Thus, the pressure regulator is sized to achieve a compromise between the different operating phases of the vehicle and with which the flow Oil allows both to dissipate the thermal energy in phases where the clutch in many product and not to compromise performance of the clutch in the other phases. Nevertheless, it is forced to focus the lubrication of the clutch to the detriment of its performance because poor performance is acceptable, though not that can seize. This is also why the exchanger is dimensioned to evacuate the thermal energy of the oil in a position of maximum dissipation.

A problem that arises and that aims to solve this invention is therefore to provide a lubricating device which permits dissipate heat energy in all circumstances without compromising the performance of the clutch.

For this purpose, the present invention provides a device of lubrication system for vehicle clutch gearbox motor, said clutch system producing raw amounts of heat energy during the early stages of operation of said clutch device and second quantities Additional during the second operating phases, said lubricating device comprising a lubricating circuit and means of distribution of said oil lubrication circuit to dissipate the thermal energy produced by said clutch system, said device having oil cooling means; and, during said early stages of operation, said dispensing means are adapted to supply a first amount of said lubricating oil circuit through said cooling means, and during said second operating phases, to provide an additional amount of oil directly in said lubrication circuit, bypassing said cooling means.

Thus one feature of the invention resides in means of distribution that not only provide oil quantities differ depending on the vehicle operating phases, but also to circulate said first amount of lubricating oil only through the cooling means in the first operating phases, for example when the clutch produces little thermal energy and to add an additional amount of oil bypassing the cooling means when the vehicle is in the second operating phases, and in particular when the clutch produces a lot of energy. the so during the first operating phases which correspond to the rolling phases normal and are the most frequent, the oil passes through the means cooling before joining the lubrication circuit means cooling which are then dimensioned for a first quantity fixed oil to a theoretical maximum temperature. In addition, when the vehicle is in an operating phase wherein the clutch produces large amounts of thermal energy, a quantity Additional oil is directly injected into the circuit lubrication.

In a particular implementation of the invention, said distribution means supplies said first amount of oil according a first control mode and said amount of additional oil in a second mode of regulation. Thus, in the early stages corresponding in particular to normal working phases, the first amount of oil for lubricating Is the clutch likely to be finely regulated to optimize the performance of the clutch, while in the high energy production phases thermal, which are less frequent, the second amount of oil can be less tightly regulated. Thus, without compromising performance it greatly simplifies the clutch construction of said means distribution.

According to an advantageous characteristic, said device comprises Furthermore, detection means and control means connected together, and said control means are adapted to control said distribution means in said first or second mode of response control to said detecting means which detects the one or respectively the other, said first or second operating phases. Thus, the control means, e.g. a solenoid valve, in response to a signal provided by the means detection, for example a tachometer or a device capable of measuring the torque engine are adapted to control the means of distribution, according to the first or the second control mode. The latter are, by example, consist of a spool valve.

Advantageously, the spool valve having an inlet and two outputs; a first connected to said cooling means and connected directly to said one second lubricating circuit and said spool is adapted to release said first output in said first phase operation and to release the two outputs in the second phases Operating. So simple, the drawer kept standing in a position where it closes the two outlets, is it suitable to be discarded this position by translation by first reading the first outlet during the first control mode, then the second output during the second control mode.

In a particular embodiment of the invention, said first output of said spool valve is provided with a device hydraulic regulation of the oil flow in response to said means control so as to precisely adjust the amount of oil needed for the lubrication without incurring the pressure fluctuations and disrupting flow control accuracy.

To avoid this disruption, said regulating device Hydraulic comprises preferably a throttle formed on the first output and on either side of which two pipes against pressure are connected to said slide valve in reaction against.

According to an alternative embodiment, the lubrication device further comprises means for supplying pressurized oil mounted on a main pipe which preferably comprise a pressure reducer to prevent the oil pressure is too important in the lubrication circuit.

Advantageously, said oil supply means under pressure comprise at least one pressure regulating valve to precisely adjust the pressure in the lubricating circuit.

Other features and advantages of the invention will emerge on reading the description given below of particular embodiments of the invention, indicative but not limiting, with reference to accompanying drawings in which:<ul><li>Figure 1 is a schematic view of a first circuit Hydraulic lubricating apparatus according to the invention in a first variant; and,</li><li>Figure 2 is a schematic view of a second circuit Hydraulic lubricating apparatus according to the invention in a second variant.</li></ul>

Figure 1 illustrates a hydraulic circuit 110 housed in a vehicle automobile, comprising an oil pump 112, fixed displacement or variable. This oil pump 112 is provided with a safety valve 114 and it is driven in rotation by an engine 116 of the vehicle automobile.

The oil pump 112 has an output 118 which allows feeding a supply line 120 to a line pressure P. determined This supply line 120 provides power to all Vehicle power bodies.

This line pressure P is regulated by means of a valve pressure control 122 driven by a given set pressure by a first solenoid valve 124. This control valve pressure 122 has a downstream outlet 126 that feeds a line 128 secondary to a secondary pressure line 128.

This secondary pressure line 128 is regulated by a reducing pressure at two outputs 130, an outlet which opens into a circuit Lubricating 132, which feeds a spool valve 134, and a output 136 which removes excess oil to a suction line 138 pump 112.

The branch line 128 supplies the first solenoid valve 124 and one second solenoid valve 140 which is adapted to control the spool valve in 1134 by the bais of a conduit 142. This line secondary 128 also supplies the lubrication of elements not shown and requiring lubrication flow just constant. The spool valve 134 has an input 144 and two outputs, first 146 and second 148.

The valve spool 134 is movable in translation between two extreme positions, on the one hand a rest position in which it closes the two outlets 146, 148 and a maximum displacement position in which it releases the two outputs 146, 148. In one position intermediate, the drawer is adapted to release the first exit 146 closing the second outlet 148.

The spool is held in the rest position by a spring, and drawer is controllable in translation by means of the second solenoid valve 140 by applying pressure in the conduit 142 to overcoming the spring biasing force.

The positioning of the spool is given by a force balance given by the spring, the control pressure in the conduit 142 given by the second solenoid valve 140 and two pressures against reaction. Both reaction against pressures allow to control fine way the oil flow through the first outlet 146. To do this, the lubrication circuit 132 includes, upstream from the first outlet 146, a throat 150 and two pipes against pressure 152, 154, of both sides of the constriction 150 and which are connected said spool valve in reaction against.

The lubrication circuit 132 has an end 156 which joins a clutch directly to lubricate and to which are connected two branches, one which is directly connected to the second output 148 and the other which passes through a cooling system or heat exchanger 158 for then join the first exit 146.

The outputs, 146, 148 converge downstream of the exchanger 158 to join together the clutch.

In addition, the detection means may comprise a not shown temperature sensor and adapted to measure the temperature of the oil lubrication system. This sensor is adapted to transmitting a signal to the control means and here in particular to the second solenoid valve 140. be described in more detail its mode operation below.

When the control pressure in the conduit 142 is zero, the drawer is in the lubrication of cut position. This possibility is advantageous in low temperature operation. It makes it possible not generate collage torque or "drag" too important in clutches, like a parasite couple would be detrimental not only the transmission efficiency but also the precision of the steering torque to be transmitted.

An increase of the control pressure is generated by the second solenoid valve 140 and in a first mode of control in response to unrepresented detection means, which detect first operating phases of the corresponding vehicle by example the normal travel and in particular to measuring the temperature oil, This increase in pressure causes a displacement of the slide and clearing, at least partially, from the first output 146. The drawer is then kept in a balanced position between the pressure control of the conduit 142 and by the difference between the two pressures of reaction against the two pipes against reaction 152, 154. Because the difference between the two pressures is against reaction proportional to the oil flow in the first outlet 146 is obtained a hydraulic regulation of this flow rate, the desired flow rate given by the control pressure.

The spool position therefore results from this regulation and is likely to be ruled out completely this first exit 146 in second operating phases. The flow rate in this first output 146 is then fixed by the loss of driving and longer depends on the position of the slide as the latter swings shut not.

If one continues to increase the control pressure in the conduit 142, during the second operating phases, for example corresponding to passages in the high range speeds, slide continues to move and gradually discovers the second exit 148, the first exit 146 remaining turn, completely discovery. This increase in control pressure is controlled by the second solenoid valve 140, in a second mode of control in open loop where the flow through the second outlet 148 depends only of the control pressure.

Thus, the lubrication flow rate is adjusted finely in normal driving situations, and less finely in those situations very dissipative energy that require lubrication flow maximum and in which the two outputs 146, 148 are free. The regulation for high flows where both outputs 146, 148 are free is less accurate, but these phases are of short duration compared to vehicle use, this has little impact on the overall performance of the transmission.

The efficiency of the gearbox is optimized in Most vehicle use phase.

Moreover, in the early stages of operation, the flow oil to the first output 146 is also the oil flow through the heat exchanger 158 and may be controlled according to the measurement of oil temperature. Thus, when the temperature sensor detects a heating oil, it can control up to the regulated flow the first outlet 146. In this way, more heat energy dissipates in exchanger 158 and the lubrication is increased. Consequently, the cooling of the clutch is increased.

With this double effect, the temperature of the oil in the circuit is controlled faster.

In a particular implementation, not shown Figure 1 but in which the hand is in Figure 2, which will be described below, the flow control to the first output 146 is replaced by a pressure regulation. To do this, removing the driving against reaction downstream of the throttle 150. This embodiment of the work very slightly degrades the flow control but it is equivalent to the previous mode if one considers that the loss of all components downstream of the constriction 150 is concave. And above all, it simplifies the hydraulic circuit.

Referring now to Figure 2, illustrating, according to another Alternatively, a hydraulic circuit in which the lubricating circuit is 2fi0 powered by a pressure reducer. This hydraulic circuit having a large number of identical elements in the preceding, the references for these items will have the same number, except the first figure which corresponds to the Figure number 1, preceded by the number of Figure 2.

Found in this Figure 2, the spool valve 234 which is powered by a secondary line 228. This secondary line 228 is powered by a power supply line 220 via the gear pressure 260.

This alternative eliminates the pressure reducer two outputs of the previous variant and greatly simplifies the circuit hydraulic. Furthermore, the pressure regulating valve 222 can easily be installed on the body of the pump 212.

Similarly to the previous variant, the secondary line 228 feeding the first solenoid valve 224 which can control the pressure regulating valve 222, and the second solenoid valve 240 which is adapted to control the spool valve 234.

The spool valve 234 also includes an inlet 244 and two outputs, 246, 248, however, a single driving against pressure 254 upstream of the constriction 250 is retained for simplify the circuit. a flow control is obtained by knowing the loss downstream components of the constriction 250.

These structural changes allow the hydraulic circuit the simplification but on the other hand, its operation is in any identical item.