Thermostatic valve for connecting an automatic transmission with an oil cooler

Abstract

In a thermostatic valve for connecting an automatic transmission with an oil cooler, wherein the connection between an inlet conduit 12 for oil coming from the transmission and an outlet conduit 13 to the oil cooler is released or blocked by means of a valve slider element 22, which is actuated by a thermostatic actuating element 16, 17 and is spring-loaded by a restoring spring 21, the valve slider element 22 with the restoring spring 21 is designed as a pressure-control valve which, with the open connection between the inlet conduit 12 for oil coming from the transmission and the outlet conduit 13 to the oil cooler, opens a bypass conduit 24 when a predetermined pressure of the oil is exceeded.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 represents an axial sectional view through a thermostatic valve in accordance with the invention in the cold state,

FIG. 2 shows the thermostatic valve in accordance with FIG. 1 with the valve element open,

FIG. 3 represents an axial sectional view through a thermostatic valve when overpressure occurs, and

FIG. 4 represents a radial sectional view through a modified embodiment of a thermostatic valve in accordance with the invention.

Claims

1. A thermostatic valve for connecting an automatic transmission with an oil cooler, having a first inlet conduit (12) for oil received from the transmission, a first outlet conduit (13) for oil delivered to the oil cooler, a second inlet conduit (14) for oil received from the oil cooler, and a second outlet conduit (15) for oil delivered to the transmission, wherein a connection between the first inlet conduit for oil received from the transmission and the first outlet conduit for oil delivered to the oil cooler is opened or blocked by means of a valve element (22) which is actuated by a thermostatic actuating element (16, 17) and is spring-loaded by means of a restoring spring (21), characterized in that the valve element (22) with the restoring spring (21) comprises a pressure-control valve positionable in a release position when the connection is open between the first inlet conduit (12) for oil received from the transmission and the first outlet conduit (13) for oil delivered to the oil cooler to open a bypass conduit (24) between the first inlet conduit (12) for oil received from the transmission and the second outlet conduit (15) for oil delivered to the transmission when a predetermined pressure of the oil is exceeded.

2. The thermostatic valve in accordance with claim 1, characterized in that the bypass conduit (24) is arranged in the actuating path of the valve element (22) such that the valve element (22), which is driven by the thermostatic actuating element, keeps the bypass conduit (24) closed up to a predetermined oil temperature.

3. The thermostatic valve in accordance with claim 1, characterized in that a valve housing (10) for the thermostatic actuating element (16, 17) and a restoring spring (21) has a receiving bore (11), into which the first and second inlet conduits (12, 14) and the first and second outlet conduits (13, 15) lead, and that a valve slider element (22) is arranged between the first inlet conduit (12) for oil received from the transmission and the first outlet conduit (13) to the oil cooler.

4. The thermostatic valve in accordance with claim 3, characterized in that the valve slider element (22) is fixedly connected with a housing (16), spring-loaded by means of the restoring spring (21), of the thermostatic actuating element, whose working piston (17) is supported on a detent (18).

5. The thermostatic valve in accordance with claim 3, characterized in that a longitudinal groove (24) is provided in the receiving bore (11), which constitutes the bypass conduit for the pressure-control valve and which is arranged such that, when the valve slider element (22) is in the release position and the bypass conduit is in the blocking position, the latter is closed, and is opened when, because of the increased pressure of the oil, the valve slider element (22) is moved past its release position which can be reached during normal operation as a function of the temperature.

6. The thermostatic valve in accordance with claim 3, characterized in that a second longitudinal groove (23) has been cut into the receiving bore (11) which, when the valve slider element (22) is in the blocking position, constitutes a bypass connection between the first inlet conduit (12) for oil received from the transmission and the second outlet conduit (15) to the transmission, which is closed in the release position of the valve slider element (22).

7. The thermostatic valve in accordance with claim 5, characterized in that the longitudinal groove (24) constituting the bypass conduit and the second longitudinal groove (23) are arranged diametrically opposite each other in the receiving bore (11).