Valve, especially expansion valve for refrigerator

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PATENT AND

Registration Office

SVE RIG E

EXPLANATORY STATEMENT No. 3QJ 435 ^lntcl F 16 k 17/04 ^KI-47 g 47, / 02 h · “□.

Patent Application. No. 15046/65 appeared on 22X1 19 &amp; 5

Validity Day of 22 XI 1965

Ans. generally available on 1 VII 1968

Ans. laid out and the pamphlet published on 7 In 1969 Priority_sas of 12 XII 1964 »(Federal Republic of Germany DT, F 44 695)

FIRM LATEST FL1T3CH, FELLIACH / STUTTGART, FEDERAL REPUBLIC OF GERMANY DT Inventor: R Götzenberger Ombud; 3 Modin

Valve, especially expansion valve for refrigeration plants

The invention relates to a valve, in particular an expansion valve for refrigeration plants. The valve is of the type consisting of a nozzle body containing a seat for a valve needle which is displaceable in its longitudinal direction in a guide in the body and abuts against the seat under the action of a spring, a longitudinally displaceable pressure pin being arranged to act upon valve needle.

In the prior art valves, the valve body is screwed together or otherwise fastened with a socket, while the valve needle is surrounded by a metal holder. Since the valve needle must be controlled precisely centered, careful machining of the peripheral surface of the holder and the hole receiving the valve needle in the holder and the holder controlling parts of the valve fitting have been absolutely necessary. In addition, an additional guide pin for the push pin must be screwed together or otherwise fastened with the socket, whose machining must also be done with great precision.

In another known valve of a similar type, the valve needle is guided by two projecting parts, curved in cross section, in cross-section, which have only a speckle contact with narrow sectors of the needle and therefore do not provide adequate control.

The object of the invention is to provide a device which provides a precisely centered control for the valve needle in relation to the valve seat. and the push pin. This is achieved by the fact that the guide surfaces of the pressure pin are arranged on the mirror body body, and that the control surfaces of the valve needle and the pressure pin are formed by three strips arranged on both sides of the valve seat, which extend in axial plane and with tangential planes abutting each cylindrical center part of the valve. respectively, the push pin. By providing the tangential surfaces of the control surfaces, they provide a linear contact with the control of the axially displaceable valve elements, thus achieving a minimal friction and correspondingly high sensitivity of the valve, while ensuring a laminar flow. Such flow control greatly avoids the blistering which adversely affects the passage of the coolant through the valve.

Married, it is desirable that the valve can be removed from the plant as a unit, without separating the valve body, valve needle and pressure pin. The. in this case, it is particularly advantageous if a protrusion for the pressure pin or the valve needle protrusion is formed on at least one of the guide surfaces of the pressure pin. respectively. the valve needle, whereby this protrusion is arranged to engage behind a ledge or oct. valve needle. This prevents the pressure pin or valve needle from falling out of the valve body upon removal of the valve assembly. In addition, it is convenient if at least one projection serving as a fuse for the valve body is formed on the peripheral surface of the valve body.

An embodiment of the device according to the invention is described below with reference to the accompanying drawing, which shows an axial cutting. through a valve assembly. In a socket or sleeve 10 having an internal thread 12 at one end and near the other end having an internal annular bead 14, a pressure spring 16 supporting the bead is inserted. The spring tapered conically to the free end, which carries one

18th In the thread 12, a generally designated valve body is screwed in. The vennil body is approximately provided at its center with a hole 24, which forms a valve seat 22. At its end facing the roof spring 16, the valve body is formed with three guide parts 26, which are equally distributed around the perimeter of the hole 24 (120 ° pitch) and which form guide for a valve needle 28 against which the pressure gauge 18 abuts, so that the valve needle is pressed against the seat 22 under the action of the spring 16. Similarly, at the other end of the valve body, there are three evenly distributed guide members for controlling a push pin 32. One of these guide members has a projection 34 for securing the pin 32, and one of the other two control members has a projection 36 for securing the valve assembly.

The entire valve body 20 is preferably made by injection molding of a plastic material, the surface of which has good sliding properties.