JPH0474570B2 - - Google Patents

Description

Detailed Description of the Invention A. Purpose of the Invention (Field of Industrial Application) The present invention provides hydraulic control of lubricating oil supplied to lubricating parts such as shafts and gears of the transmission in transmissions for automobiles and the like. Regarding the valve to be done.

(Prior art) In the past, the lubricating oil supply oil path to the lubricating part of a transmission was arranged downstream of the hydraulic control valve for clutch and brake operation of the transmission, and the oil flowing out from this hydraulic control valve was kept as it was. It is designed to be supplied to the lubricating section. In this case, in order to prevent the lubricating oil pressure from becoming too high, a lubricating oil pressure control valve is installed in the lubricating oil supply oil passage, and if the lubricating oil pressure exceeds a predetermined oil pressure, part of the lubricating oil is transferred to the drain passage. It was designed to flow into the oil sump through the oil sump.

On the other hand, in a transmission equipped with a torque converter (particularly a transmission equipped with a torque converter with a lock-up clutch), oil flowing out from the torque converter (hereinafter also referred to as torque converter) passes through an oil cooler and is cooled. It is often returned to the oil sump, and an example of such a structure is disclosed in Japanese Patent Publication No. 59-43661, for example. However, in the case of such a configuration, for example, the flow rate to the oil cooler when the lock-up clutch is activated is determined by the excess torque converter internal pressure from the torque converter check valve and a small amount of oil supplied that does not reduce the required torque converter internal pressure. As a result, the oil cooler flow rate decreases.
Cooling may become insufficient and the oil temperature may rise.

For this reason, conventionally, the lubricating oil passage is branched via a check valve or orifice, and this branched oil passage is communicated with the cooler oil passage, so that a part of the lubricating oil flows into the cooler. was also used.

(Problem to be solved by the invention) Although it is possible to solve the problem of insufficient flow to the oil cooler in this way,
Conversely, this time, there is a risk that the amount of lubricating oil will be insufficient and the lubricating oil pressure will drop.

The present invention has been made in view of such problems, and an object of the present invention is to make it possible to ensure lubricating oil pressure and also increase the flow rate of the cooler.

B. Structure of the Invention (Means for Solving the Problem) As a means for achieving the above object, in the present invention, a lubricating pressure control valve having the following structure is disposed on the lubricating oil path. This lubrication pressure control valve is
The lubricating oil passage is disposed in the lubricating oil passage, and when the lubricating oil pressure exceeds a first predetermined oil pressure, the lubricating oil passage is communicated with the cooler oil passage to cause a part of the lubricating oil to flow into the cooler oil passage, and further, When the lubricating oil pressure exceeds a second predetermined oil pressure higher than the first predetermined oil pressure, the lubricating oil passage is also communicated with the drain oil passage so that a part of the lubricating oil flows out to the cooler oil passage and the drain oil passage. It is composed of

(Function) When using the lubrication pressure control valve configured as described above, all the oil supplied to the lubrication oil passage will flow to the lubricating part until the lubrication oil pressure in the lubrication oil passage exceeds the first predetermined oil pressure. However, when the amount of lubricating oil increases and becomes more than necessary, and the lubricating oil pressure exceeds the first predetermined oil pressure, the lubricating oil path is communicated with the cooler oil path by this control valve, and the excess lubrication is removed. The oil is drained into the cooler oil passage to supplement the cooler flow rate. Furthermore, when the cooler flow rate exceeds the required amount and the lubricating oil pressure exceeds the second predetermined oil pressure, the lubricating oil path is also communicated with the drain oil path by this control valve, and lubrication and supply to the cooler are performed. Any excess oil is then returned directly to the oil sump via the drain line.

(Example) Preferred examples of the present invention will be described below with reference to the drawings.

FIG. 1 shows a lubrication pressure control valve 50 according to the present invention.
FIG. 2 is a diagram showing a hydraulic circuit of a torque converter 5 of a transmission having a transmission. This torque converter 5 has a lock-up clutch 6 that can directly connect an impeller 5a and a turbine 5b, and the operation of this lock-up clutch 6 is controlled according to the ON/OFF operation of two solenoid valves 7 and 8. The lockup shift valve 20, lockup control valve 30, and lockup timing valve 40 are operated by the lockup shift valve 20, lockup control valve 30, and lockup timing valve 40.

This lock-up clutch 6 is operated at a predetermined speed stage to improve drivability and fuel efficiency.
0 and 40, the capacity is controlled in four stages: a weak lockup control region, a strong lockup control region, a complete lockup region, and a deceleration lockup control region.

First, consider the case where both solenoid valves 7 and 8 are OFF. From oil sump 1 to oil path 10
1 and is sucked in from the hydraulic pump 2 to the oil passage 102.
The oil discharged is regulated to a predetermined line pressure by a regulator valve 3 connected via a branch oil line 103, and is supplied to a gear setting clutch and brake via an oil line 104. . Also,
An oil passage 105 branched from the oil passage 104 is connected to a modulator valve 4, and the line pressure of the oil passage 105 is regulated to a modulator pressure by the modulator valve 4, and then supplied to the oil passage 106.

The first and second solenoid valves 7 and 8
In the case of OFF, orifices 7a and 8
The oil passages 7b and 8b communicating through the solenoid valves 7 and 8 are closed by the spools of the solenoid valves 7 and 8,
Therefore, the modulator pressure from the oil passage 106 acts on the oil passages 109, 110, and 111. Therefore, modulating pressure acts on both ends of the lock-up shift valve 20 through the oil passages 109 and 106a, and the spool 21 of the valve 20 is moved to the right in the figure by the spring 22. Also, via oil passages 110 and 111,
Modulating pressure acts on the left end of the lockup control valve 30 and the right end of the lockup timing valve 40, and the control valve 30
spool 31 moves to the right, timing valve 40
The spool 41 is moved to the left. At this time, the line pressure supplied from the regulator valve 3 to the oil passage 107 is supplied to the oil passage 108 via the groove of the spool 21 of the shift valve 20, and from the oil passage 108 to the release side of the lock-up clutch 6. Since the liquid is supplied into the passage 6a, the lock-up clutch 6 is turned off.

Note that the oil discharged from the torque converter 5 into the oil passage 112 flows into the cooler oil passage 115 via the torque converter check valve 9, and the oil discharged from the torque converter 5 into the oil passage 113 flows through the shift valve 20. The oil flows from the groove of the spool 21 through the oil path 114 to the cooler oil path 115 , then passes through the oil cooler 11 to be cooled, and is returned to the oil sump 1 through the oil path 116 . In addition, in order to protect the cooler oil passage 115 and the cooler 11, a cooler relief valve 1 is provided.
0 is connected to the cooler oil passage 115.

Next, consider the case where the lockup control is weak. This region is set when the vehicle speed is low, and is generated by turning on the first solenoid valve 7 and keeping the second solenoid valve 8 off. When the first solenoid valve 7 is turned ON, the modulator pressure in the oil passage 109 acting on the left end of the shift valve 20 is released, so the spool 21 is moved to the left by the modulator pressure acting on the right end from the oil passage 106a. When the spool 21 is moved to the left, the line pressure supply direction from the oil passage 107 is switched to the oil passage 113, and the oil passage 113 is switched to the oil passage 113.
Line pressure is supplied to the inside of the torque converter 5 from the inside of the torque converter 5, and the internal pressure of the torque converter 5 increases. As a result, the lock-up clutch 6 is pushed toward the engagement side, and back pressure is generated within the release-side passage 6a.

The internal pressure of the torque converter acts in the direction of engaging the lock-up clutch 6, and the back pressure of the torque converter acts in the direction of releasing it. Groove of spool 21 of valve 20 and oil passage 11
8 to a control valve 30, and this control valve 30 controls the oil passage 11.
8 and an oil passage 113a branched from an oil passage 113 having line pressure, the torque converter back pressure is controlled.

That is, the torque converter back pressure is controlled by the control valve 30, and the operation of the control valve 30 is caused by the throttle oil pressure supplied through the oil passage 121 and acting to push the spool 31 to the left, and the oil passage 119. Spool 3 through
The torque converter back pressure acts to push the spool 31 to the left, the modulator pressure is supplied via the oil passage 110 and acts to push the spool 31 to the right, and after being regulated by the torque converter check valve 9, the oil passage It is controlled by a balance with a constant pressure supplied via 122 and 120 that acts to push spool 31 to the right. In this case, spool 3
The influence of the modulator pressure pushing 1 to the left is large, and the torque converter back pressure in the oil passage 118 is only slightly lower than the line pressure in the oil passage 113a. For this reason,
The lock-up clutch 6, which is engaged and released by the differential pressure between the internal pressure of the torque converter and the back pressure, is pressed in the engagement direction with a weak force, but the lock-up capacity at this time is small and falls into a weak lock-up control region. .

Next, consider the strong lockup control region. This range is set by turning on the second solenoid valve 8 as the vehicle speed increases from the weak lockup control range. The second solenoid valve 8
When turned ON, the modulator pressure supplied to the oil passages 110 and 111 is released. For this reason,
Although the modulator pressure that acts on the left end of the timing valve 40 decreases, the throttle pressure that acts to move the spool 41 to the right via the oil passage 117 is not yet high enough, and the spool 41 is not attached to the spring 42. It is held in a state where it is moved to the left by the force.

On the other hand, in the control valve 30, as the modulator pressure from the oil passage 110 that acts to move the spool 31 to the right decreases, the force pushing the spool 31 to the right decreases, which causes the line pressure in the oil passage 113a to decrease. In contrast, the back pressure of the torque converter in the oil passage 118 becomes lower. When the torque converter back pressure decreases in this way, the difference between the torque converter internal pressure and the back pressure increases, and the lock-up clutch 6 is pushed more strongly toward the engagement side than in the lock-up control weak region, increasing the lock-up capacity. Become. however,
In this state, the back pressure is not zero and the lock-up clutch 6 is pushed back toward the release side by the amount of back pressure, so the lock-up is not completely locked up and the lock-up control is in a strong region.

When the vehicle speed further increases from this state, the throttle opening also increases, and the throttle pressure supplied from the oil passages 117 and 121 also increases. As the throttle pressure increases, the spool 41 is moved to the right against the spring 42 by the throttle pressure acting from the oil passage 117 to push the spool 41 of the timing valve 40 to the right. This movement of the spool 41 to the right cuts off the communication between the oil passage 122 and the oil passage 120, and the hydraulic pressure from the oil passage 120 acting on the left end of the control valve 30 disappears. Furthermore, since the throttle pressure from the oil passage 121 has increased, the spool 31 of the control valve 30 is pushed to the left with a considerably stronger force than in the strong lockup control region. Therefore, communication between the oil passage 113a and the oil passage 118 is cut off, and the oil passage 11 having torque converter back pressure is cut off.
8 is in communication with the drain, and the torque converter back pressure becomes zero, so that the lock-up clutch 6 is fully engaged, resulting in a complete lock-up region.

The above is the normal lockup control, but in addition to this, a deceleration lockup control area may be set. This range is set during deceleration, and is set by turning on the first solenoid valve 7, controlling the duty ratio of the second solenoid valve 8, and controlling the operation of the control valve 30. By controlling the duty ratio of the second solenoid valve 8 in this way, the capacity of the lock-up clutch 6 can be appropriately controlled in the lock-up control weak region and strong region according to the duty ratio, and thereby the accelerator pedal When the engine is returned to its original position, lockup can be performed while the engine is braking.

As described above, the amount of oil supplied to the oil cooler 11 through the torque converter 5 is determined by the amount of oil supplied from the regulator valve to the oil passage 107, and this amount of oil is determined by the amount of oil supplied to the oil passage 107 from the regulator valve. It varies depending on the control, and becomes smaller in the weak and strong lockup control regions.
Therefore, in this example, the lubricating pressure control valve 5
0 is arranged to ensure the amount of oil to the cooler oil passage 115.

This lubricating pressure control valve 50 will be explained.
The valve 50 has a spool 51 and a spring 52 that urges the spool 51 to the right, as shown in an enlarged view in FIG. 2A. Spool 5
The right end surface of the spool 51 faces the lubricating oil passage 123 that guides the lubricating oil from the regulator valve 3 to each lubricating part in the transmission, and the spool 51 is moved to the left by the lubricating oil in the lubricating oil passage 123. under the pressure of As can be clearly seen from FIG.
4 and a drain oil passage 125 that communicates with the drain.

When the lubricating oil pressure in the lubricating oil passage 123 is low,
The spool 51 is held in the state of being moved to the right by the biasing force of the spring 52, and in this state, as shown in FIG. 2A, the land surface of the spool 52 causes
Both oil passages 124 and 125 are closed. Therefore, from the regulator valve 3 to the lubricating oil path 12
The entire amount of the lubricating oil spilled in step 3 is supplied to the lubricating section.

When the amount of oil flowing into the lubricating oil passage 123 increases and the lubricating oil pressure rises, and this lubricating oil pressure exceeds the first predetermined oil pressure, the force that pushes the spool 51 to the left increases due to the lubricating oil pressure, and the spool 51 is moved to the left against the spring 52. This allows the second
As shown in Figure B, the groove 51a of the spool 51 communicates with the oil passage 124. As shown in the figure, this groove portion 51a communicates with the left end surface of the spool 51 via axial communication lines 51b, 51b, and the lubricating oil path 1
A part of the lubricating oil in 23 flows out into oil passage 124 through communication hole 51b and groove 51a, and then flows into cooler oil passage 115. That is, when the amount of lubricating oil increases and the lubricating oil pressure increases, the excess lubricating oil is spilled into the cooler oil passage 115, thereby maintaining the lubricating oil pressure in the lubricating oil passage 123 at a predetermined level, and increasing the oil pressure in the cooler oil passage 115. Increase flow to.

From the above state, the amount of lubricating oil further increases and the lubricating oil pressure further increases, and this lubricating oil pressure becomes the first lubricating oil pressure.
If the second predetermined oil pressure, which is higher than the predetermined oil pressure of
As shown in the figure, the drain oil passage 125 is unblocked by the land surface of the spool 51, and the lubricating oil passage 125 is unblocked.
23 also communicates with the drain oil passage 125. In other words, the amount of oil supplied to the lubricating section and the cooler oil path 11
If the amount of oil supplied to both channels 5 and 5 is sufficient and there is an additional amount of oil, drain this excess oil to drain oil path 1.
25 directly to the oil sump to prevent the internal pressures of the lubricating oil passage 123 and the cooler oil passage 115 (and 124) from becoming too high.

C. Effects of the Invention As explained above, according to the present invention, until the lubricating oil pressure in the lubricating oil passage exceeds the first predetermined oil pressure, all the oil supplied to the lubricating oil passage flows to the lubricating part. When the amount of lubricating oil increases and the lubricating oil pressure exceeds the first predetermined oil pressure, the lubricating oil passage is communicated with the cooler oil passage and the excess lubricating oil is discharged into the cooler oil passage, and furthermore, the cooler flow rate is also increased. When the required amount is exceeded and the lubricating oil pressure exceeds the second predetermined oil pressure, the lubricating oil path is also communicated with the drain oil path, and the remaining oil after lubricating and supplying to the cooler is drained into the drain oil path. Since the lubricating oil is returned directly to the oil sump via the oil sump, it is possible to supplement the amount of oil to the oil cooler while always ensuring a sufficient amount of lubricating oil, thereby improving the oil cooling ability. Further, both the lubricating oil pressure and the cooler oil pressure can be suppressed to below a predetermined oil pressure to prevent both pressures from becoming too high.

[Brief explanation of the drawing]

FIG. 1 is a hydraulic circuit diagram around a torque converter having a lubricating pressure control valve according to the present invention, and FIGS. 2A to 2C are sectional views showing the lubricating pressure control valve. 1...Oil sump, 2...Hydraulic pump, 3...
... Regulator valve, 5 ... Torque converter, 6 ... Lock-up clutch, 7, 8 ... Solenoid valve, 11 ... Oil cooler, 20 ...
...Lockup shift valve, 30...Lockup control valve, 40...Lockup timing valve, 50...Lubricating pressure control valve.

Claims (1)

[Scope of Claims] 1. A valve disposed in a lubricating oil passage that supplies lubricating oil from a lubricating oil supply source to a lubricating section of a transmission to control lubricating oil pressure in the lubricating oil passage, comprising: When the lubricating oil pressure exceeds a first predetermined oil pressure, the lubricating oil path is communicated with a cooler oil path that communicates with an oil cooler, and a part of the lubricating oil in the lubricating oil path flows out to the cooler oil path. , when the lubricating oil pressure exceeds a second predetermined oil pressure higher than the first predetermined oil pressure, the lubricating oil passage is also communicated with a drain oil passage, and a part of the lubricating oil in the lubricating oil passage is transferred to the cooler. A lubrication pressure control valve for a transmission, characterized in that the lubrication pressure control valve is configured to allow oil to flow into an oil passage and the drain oil passage.