JPH10176748A - Oil cooler device for transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep an oil temperature in a transmission at a proper value and ensure excellent lubrication performance even during starting in a low atmosphere temperature state and to prevent the damage of durability of a radiator due to rapid inflow of high temperature lubrication oil to the radiator. SOLUTION: This oil cooler device for a transmission is provided with a cooling route 23 to feed lubrication coil to respective slide parts of a transmission 20 from the oil pan 21 of a transmission 20 through an external radiator 22; a bypass passage 24 to short-circuit upper stream and downstream of the radiator 22; and a thermo sensing value 26 to selectively open and close a bypass passage 24 and the by pass passage 25 of the radiator 22 such that by sensing an oil temperature in an oil pan 21, the oil temperature is kept at a proper value, at the upperstream of the radiator 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an oil cooler for a transmission.

[0002]

2. Description of the Related Art In a transmission, an oil cooler device is provided in order to suppress an excessive rise in oil temperature from the necessity of maintaining good lubrication performance of each part (Japanese Patent Laid-Open No. 7-103316, Japanese Utility Model Laid-Open No. 7-103). No. 28261).

FIG. 3 shows the configuration of an oil cooler device applied to the transmission of a large vehicle such as a truck. A radiator 2 (cooler) is provided outside the transmission 1, and lubricating oil is provided between the transmission 1 and the transmission. Cooling path 7 is formed. The lubricating oil is stored in the oil pan 3, and when the oil pump 4 is driven, it is sucked out of the oil pan 3 through the strainer 5 and supplied to the external radiator 2. In a normal operation state, cooling is performed by passing through the radiator 2, and is supplied to each sliding portion of the transmission 1 through the oil filter 6.

[0004] A bypass passage 8 for short-circuiting the front and rear of the radiator 2 is formed in the cooling passage 7, and a release valve 9 is provided at the entrance of the passage. When the pressure on the upstream side of the radiator 2 exceeds the set load of the spring, the release valve 9 opens the bypass passage 8 to release the pressure on the radiator 2 upstream to the oil filter 6. Reference numeral 10 denotes a bypass valve for releasing the pressure on the upstream side to the downstream side when the oil filter 6 is clogged or the like, and reference numeral 11 denotes a relief valve for regulating the discharge pressure of the oil pump 4.

[0005]

In such a conventional example, the lubricating oil in the radiator 2 has a low temperature when the engine is started in a low temperature state, and the viscous resistance of the oil when passing through a narrow core passage is large. Become. Therefore, even if the oil temperature in the oil pan 3 rises to a high temperature state, the relief valve 9 does not easily switch to the closing side, and the lubricating oil hardly flows to the radiator 2, and the cooling effect becomes insufficient. There was a possibility that the oil temperature in the transmission 1 would rise excessively. Further, when the viscous resistance in the radiator 2 decreases and the relief valve 9 closes the bypass passage 8, high-temperature oil flows into the radiator 2, and the durability (heat cycle) of the radiator 2 is increased by a rapid temperature change. In some cases, it was lost.

An object of the present invention is to eliminate such a problem and improve the durability.

[0007]

According to a first aspect of the present invention, a cooling path for supplying lubricating oil from an oil pan of a transmission to each sliding portion of a transmission via an external radiator, and an upstream side of the radiator. In a transmission oil cooler device including a bypass passage that short-circuits the downstream side and valve means for controlling the bypass flow rate,
As a valve means for controlling the bypass flow rate, a thermo-sensing valve upstream of the radiator is provided which senses the oil temperature in the oil pan and selectively opens and closes the bypass passage and the passage through the radiator so as to maintain the oil temperature at an appropriate temperature. To be provided.

In the second invention, a cooling path for supplying lubricating oil from the oil pan of the transmission to each sliding portion of the transmission via an external radiator is short-circuited between the upstream side and the downstream side of the radiator. In a transmission oil cooler device including a bypass passage and valve means for controlling the bypass flow rate, a bypass means for sensing the oil temperature in an oil pan and maintaining the oil temperature at an appropriate temperature as a valve means for controlling the bypass flow rate. A thermosensing valve for selectively opening and closing the passage and the passage of the radiator is provided downstream of the radiator.

[0009]

In the first aspect, when the oil temperature in the oil pan is low, the thermosensing valve opens the bypass passage and closes the passage of the radiator. Therefore, the lubricating oil is supplied from the bypass passage to each sliding portion of the transmission. When the oil temperature in the oil pan exceeds a predetermined value, the thermosensing valve opens a passage for the radiator and closes the bypass passage. For this reason, the lubricating oil is cooled by passing through the radiator and supplied to each sliding portion of the transmission.

By the operation of the thermosensing valve, the oil temperature in the transmission is kept at an appropriate temperature. When the engine is started in a low temperature state, the viscosity resistance of the lubricating oil in the radiator increases, but when the oil temperature in the oil pan exceeds a predetermined value, the lubricating oil is supplied from the oil pan to the radiator. That is, since the lubricating oil starts flowing to the radiator without waiting for the viscosity resistance of the lubricating oil in the radiator to decrease, it is possible to effectively prevent the oil temperature in the transmission from excessively rising. Further, since the oil temperature entering the radiator is not so high, the effect of improving the durability (heat cycle) of the radiator can be expected.

In the second aspect of the present invention, the thermosensing valve is provided not on the upstream side of the radiator but on the downstream side of the radiator. The heat of the lubricating oil is transmitted from the upstream side to the inlet side. Therefore, the temperature change of the radiator when lubricating oil starts flowing from the oil pan becomes gentle, and the durability of the radiator is improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 20 denotes a transmission, 21 denotes an oil pan thereof, and a radiator 22 (cooler) is provided outside the transmission 20.
Cooling path 23 for lubricating oil between transmission 20
Is formed. A bypass passage 24 that short-circuits the front and rear of the radiator 22 is formed in the cooling passage 23, and the bypass passage 2 (a part of the cooling passage 23) of the radiator 22 and the bypass passage 2
A thermo-sensing valve 26 for selectively opening and closing 4 is interposed on the upstream side of the radiator 22.

The thermosensing valve 26 has two positions 3
It comprises a spool valve 26a of a port and a pipe 26b filled with wax, and the pressure of the wax is introduced to the pressure receiving surface of the spool valve 26a. When the acting force acting on the pressure receiving surface is smaller than the opposing force of the spring, the spool valve 26a
Opens the bypass passage 24 and the passage 25 of the radiator 22
When the temperature of the wax rises and the acting force of the pressure receiving surface overcomes the opposing force of the spring, the radiator 2
The second passage 25 is opened and the bypass passage 24 is closed.
The tip of the pipe 26b is formed in a wax reservoir 26c, which is inserted into the lubricating oil in the oil pan 21 as a temperature detecting unit.

The lubricating oil in the oil pan 21 is sucked out of the oil pan 21 through the strainer 29 by the rotation of the oil pump 27. When the oil temperature in the oil pan 21 is low, the thermosensing valve 26 opens the bypass passage 24 and closes the passage 25 of the radiator 22. Therefore, the lubricating oil from the oil pump 27 is supplied from the bypass passage 24 to each sliding portion of the transmission 20 through the oil filter 28. When the oil temperature in the oil pan 21 exceeds a predetermined value, the thermo-sensing valve 2
6 opens the passage 25 of the radiator 22 to open the bypass passage 2
Close 4. Therefore, the lubricating oil from the oil pump 27 flows to the radiator 22, is cooled by passing through the radiator 22, and is supplied from the oil filter 28 to each sliding portion of the transmission 20. Reference numeral 30 denotes a relief valve for regulating the discharge pressure of the oil pump.

As described above, the oil temperature in the transmission 20 is maintained at an appropriate temperature by the operation of the thermosensing valve 26. When the engine is started at a low temperature, the viscous resistance of the lubricating oil in the radiator 22 increases, but depends on the temperature of the oil in the oil pan 21. Lubricating oil is supplied to 22. That is, since the lubricating oil is cooled through the radiator 22 without waiting for the viscous resistance in the radiator 22 to decrease, it is possible to prevent the oil temperature in the transmission 20 from excessively increasing. In addition, since the oil temperature that starts to enter the radiator 22 is not so high, an effect of improving the durability (heat cycle) of the radiator 22 can be expected.

In the embodiment shown in FIG. 2, the thermosensing valve 26 is provided downstream of the radiator 22, and selectively opens and closes the bypass passage 24 and the passage 25 of the radiator 22. According to this, even when the thermosensing valve 26 closes the passage 25 of the radiator 2, the heat of the lubricating oil is transmitted to the inlet of the radiator 22 from the upstream side. Therefore, the lubricating oil in the radiator 22 is warmed, the temperature change of the radiator 22 when the lubricating oil from the oil pump 27 starts to flow becomes gentle, and the effect of improving the durability of the radiator 22 is obtained. .

When the thermosensing valve 26 is configured to open the bypass passage 24 to the oil pan 21 via the drain passage instead of closing the passage 25 of the radiator 22 in the illustrated position, the bypass passage 24 is opened. Even when it is open, the lubricating oil flows slightly through the radiator 22, and the temperature change when the lubricating oil from the oil pump starts flowing to the radiator 22 can be further moderated at the time of starting in a low temperature state. . In FIG. 2, the same components as those in FIG. 1 are denoted by the same reference numerals.

[0018]

According to the first invention, a cooling path for supplying lubricating oil from the oil pan of the transmission to each sliding portion of the transmission via an external radiator, and an upstream side and a downstream side of the radiator In a transmission oil cooler device having a bypass passage for short-circuiting the valve and a valve means for controlling the bypass flow rate, the oil temperature in the oil pan is sensed as a valve means for controlling the bypass flow rate and the oil temperature is adjusted to an appropriate temperature. A thermo-sensing valve is provided upstream of the radiator to selectively open and close the bypass passage and the radiator passage so that the oil temperature in the transmission can be maintained at an appropriate temperature even when starting at low temperatures. Good lubrication performance can be ensured. In addition, high-temperature lubricating oil does not suddenly flow into the radiator, and the durability of the radiator is also improved.

According to the second invention, the cooling path for supplying lubricating oil from the oil pan of the transmission to each sliding portion of the transmission via the external radiator, and the upstream and downstream sides of the radiator are provided. In a transmission oil cooler device having a bypass passage to be short-circuited and valve means for controlling the bypass flow rate, a valve means for controlling a bypass flow rate senses an oil temperature in an oil pan and maintains the oil temperature at an appropriate temperature. Since the thermo-sensing valve that selectively opens and closes the bypass passage and the passage of the radiator is provided downstream of the radiator, even if the bypass passage is open, the heat of the lubricating oil flows from the upstream to the entrance of the radiator. As a result, in addition to the effect of the first aspect, the effect that the durability of the radiator can be effectively improved can be obtained.

[Brief description of the drawings]

FIG. 1 is a cooling path diagram showing an embodiment of the present invention.

FIG. 2 is a cooling path diagram showing another embodiment.

FIG. 3 is a schematic diagram illustrating a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 20 transmission 21 oil pan 22 radiator 23 cooling path 24 bypass passage 25 radiator passage 26 thermosensing valve 27 oil pump 28 oil filter 29 strainer

Claims (2)

[Claims] A cooling path for supplying lubricating oil from an oil pan of the transmission to each sliding portion of the transmission via an external radiator; a bypass path for short-circuiting an upstream side and a downstream side of the radiator; In a transmission oil cooler device having valve means for controlling the bypass flow rate, a bypass passage and a radiator are provided as valve means for controlling the bypass flow rate so as to sense the oil temperature in the oil pan and maintain the oil temperature at an appropriate temperature. An oil cooler device for a transmission, characterized in that a thermosensing valve for selectively opening and closing the via passage is provided upstream of the radiator. 2. A cooling path for supplying lubricating oil from an oil pan of the transmission to each sliding portion of the transmission via an external radiator, a bypass path for short-circuiting the upstream and downstream sides of the radiator, In a transmission oil cooler device having valve means for controlling the bypass flow rate, a bypass passage and a radiator are used as valve means for controlling the bypass flow rate so as to sense the oil temperature in the oil pan and maintain the oil temperature at an appropriate temperature. An oil cooler device for a transmission, wherein a thermo-sensing valve for selectively opening and closing the passage is provided downstream of the radiator.