JPS61228149A - Hydraulic controller for transmission - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (b) Industrial application fields The present invention relates to a hydraulic control device for a transmission.

(b) Conventional technology As a conventional hydraulic control device for a transmission, for example,
There is one shown in Publication No. 9-77155. In this transmission hydraulic control device, line pressure is regulated according to throttle pressure (and gear ratio), and throttle pressure is controlled based on engine intake pipe negative pressure. That is, the throttle pressure is set to decrease as the engine intake pipe negative pressure increases. However, the line pressure is not allowed to fall below a predetermined minimum value.

That is, once the line pressure decreases to a predetermined minimum value, it is thereafter maintained at the minimum value even if the engine intake pipe negative pressure increases. An example of such hydraulic characteristics is shown in FIG. 9.

(c) Problems to be Solved by the Invention The line pressure characteristics obtained by the conventional transmission hydraulic control system are set as shown in FIG. 9 for the following reason. That is, the engine torque changes as shown by the solid line in FIG. 9 according to the negative pressure in the engine intake pipe. The maximum torque is achieved when the negative pressure is 0 (or a predetermined positive pressure value when using a turbocharger), and when the negative pressure is 0, for example, 400
The torque becomes 0 at mmHg, and the negative pressure further increases in the engine brake state (reverse drive state). Even in the engine braking state, the capacity of clutches, pulleys, etc. of transmissions such as automatic transmissions and continuously variable transmissions is required to cope with the reverse driving force, so the engine torque increases as shown by the broken line in Figure 1O. It is necessary to secure a capacity that can transmit a value in which the negative part is folded back to the positive side. Therefore, the line pressure characteristics are set high so that the torque indicated by the broken line can be transmitted even in a region where the negative pressure in the engine intake pipe is large. Therefore, when the negative pressure is around 400 mmHg, the throttle pressure and the line pressure regulated accordingly are higher than necessary. This area is used during steady driving and is the area that is used the longest, but if the line pressure is higher than necessary in this area, the oil pump loss increases and the efficiency of the transmission decreases. This is a major cause of this. Transmission efficiency is greatly affected by line pressure V
This invention has a particularly large effect on belt-type continuously variable transmissions.6 The present invention aims to solve the above-mentioned problems.

(d) Means for solving the problems The present invention provides hydraulic characteristics that approximate the required torque characteristics by using two diaphragms in which the direction of force applied during negative pressure is opposite to each other and the pressure receiving area is different. The above problem is solved by obtaining the following. That is, in the hydraulic control device for a transmission according to the present invention, the vacuum diaphragm unit is arranged parallel to the first diaphragm and has a pressure receiving area larger than the first diaphragm. s2
a diaphragm; a negative pressure chamber defined between the first diaphragm and the second diaphragm; a rod that transmits the pushing force of the first diaphragm to the pressure regulating valve; When the distance between the first diaphragm and the first diaphragm, which applies a force in the plane on the acting side, decreases to a predetermined value (that is, the second diaphragm is displaced by a predetermined amount toward the first diaphragm). (time) a transmission member capable of transmitting a pushing force between the two, and a second spring that applies a force to the second diaphragm from a surface on the negative pressure chamber side to a surface on the atmospheric pressure acting side.

(e) Operation When the engine intake pipe negative pressure is relatively low, the second diaphragm is pushed by the second spring and is displaced in a direction away from the first diaphragm. Therefore, the transmission member is in a state in which it is unable to transmit the pushing force of the second diaphragm to the first diaphragm, and the 882 Guiaphragm is in a state in which it does not function at all with respect to the rod. In this state, only the pushing force of the first diaphragm is transmitted to the spool of the pressure regulating valve via the rod. As the negative pressure increases, the first diamond slam receives a force that reduces the force of the first spring, so the force acting on the rod gradually decreases.

In other words, the hydraulic pressure regulated by the pressure regulating valve decreases as the negative pressure increases.As the negative pressure in the engine intake pipe increases, the difference between atmospheric pressure and negative pressure acts on the second diaphragm. The force gradually increases and the second diaphragm
It is displaced in a direction that compresses it against the force of the spring. When the negative pressure reaches a predetermined value, the second diaphragm becomes capable of transmitting force to the first diaphragm via the transmission member. When the negative pressure further increases, the second diaphragm becomes in a state where it applies a pushing force to the il diaphragm, and the force from the first diaphragm and the force from the second diaphragm act on the rod in combination. The force of the first diaphragm generated by negative pressure decreases as the negative pressure increases, and the force of the second diaphragm generated by negative pressure increases as the negative pressure increases, but the pressure received by the second diaphragm decreases as the negative pressure increases. Since the area is larger than the pressure receiving area of the first diaphragm, the influence of the force of the second diaphragm is greater, and as a result, a force that increases as the negative pressure increases acts on the rod. Therefore, the hydraulic pressure regulated by the pressure regulating valve increases as the negative pressure increases. As a result, the oil pressure obtained by the pressure regulating valve decreases as the negative pressure increases when the negative pressure is below a predetermined value, and increases as the negative pressure increases when the negative pressure value exceeds the predetermined value. The hydraulic characteristics are as shown in . When hydraulic pressure (throttle pressure) having such characteristics is applied to the line pressure regulating valve, line pressure characteristics as shown in FIG. 3 can be obtained. This makes it possible to obtain line pressure characteristics that approximate the required torque characteristics. Furthermore, if a spring that always applies force to the spool of the pressure regulating valve is provided, the pressure regulating value can be adjusted to the hydraulic characteristics shown in Fig. 6 by adjusting the setting force of this spring ring and the second spring. can. Also, the pressure receiving area of the first diaphragm and the second
By adjusting the ratio of the pressure receiving area of the diaphragm,
The degree of change in the pressure regulation value with respect to the change in negative pressure can be set arbitrarily.

(F) Embodiment (First Embodiment) A hydraulic control device for a transmission, which shows a first embodiment of the present invention in FIG. 1, has a vacuum diaphragm unit 10 and a throttle valve 12 which is a pressure regulating valve. There is. The vacuum diaphragm unit IO has two diaphragms arranged in parallel to each other in the casing 14, that is, a first
It has a diaphragm 16, a second diaphragm, and a ram 18. The second diaphragm 18 is fixed by being sandwiched between a fixing member 20 and a fixing member 22 provided in the casing 14, and the first diaphragm 1
6 is fixed by being sandwiched between the casing 14 and the fixing member 20.

A negative pressure chamber 24 is defined by the first diaphragm 16, the second diaphragm 18, and the fixing member 20. In addition,
The second diaphragm 18 has a pressure receiving area approximately twice that of the first diaphragm 16. An atmospheric pressure chamber 26 is provided on the surface of the first diaphragm 16 opposite to the negative pressure chamber 24, and an atmospheric pressure chamber 28 is provided on the surface of the second diaphragm 18 opposite to the negative pressure chamber 24. It is provided. The negative pressure chamber 24 includes a passage 20a provided in the fixing member 20 and the fixing member 22.
It is connected to a negative pressure inlet 22b by a passage 22a provided in the. The negative pressure inlet 22b is connected to the intake pipe of the engine. Note that a sealing member 30 is provided between the fixing member 22 and the casing 4 to prevent leakage of negative pressure. First diaphragm 16 and second diaphragm 18
A first spring 32 is provided between the first spring 32 and the first spring 32, which applies a force that moves the two away from each other. Further, a second spring 34 is provided between the second diaphragm 18 and the fixing member 20, which applies a force in a direction to move the 82 diaphragm 18 away from the first diaphragm 16. A transmission member 36 is provided integrally with the first diaphragm 16.

When the second diaphragm 1 is displaced by the second spring 34 as shown in the upper half of FIG. As shown, the second diaphragm 18 is in contact with the M2 diaphragm 18 when it is in the central position. Further, a metal fitting 38 is fixed to the atmospheric pressure chamber 26 side of the $1 diaphragm 16, and a rod 40 is connected to this metal fitting 38 by a screw. Casing 1
4 is provided with an integral mounting bracket 42, and the vacuum diaphragm unit 10 is attached to the throttle valve 12 of the valve body 44 by means of a screw provided on the outer periphery of the mounting bracket 42.
is installed at the location provided. The throttle valve 12 is comprised of a spool 48 fitted into a valve hole 46. The valve hole 46 has five ports) 46a to 46.
e is provided. Ports 46a and 46c communicate with oil passage 50, which is a throttle pressure circuit, and are connected to boat 46.
b communicates with the line pressure oil passage 52, and boats 46d and 46e are drain ports. Spool 48 is the first
By draining a portion of the oil supplied from port 46b to port 46d at the pressure regulating position shown in the figure, boat 46
The pressure is adjusted so that the oil pressure of a, that is, the oil pressure of the oil passage 50, is balanced with the force acting on the spool 4B from the rod 40.

Next, the operation of this embodiment will be explained. Negative pressure inlet 22
b is connected to the engine intake pipe, and engine intake pipe negative pressure acts on the negative pressure chamber 24 via the passage 22a and the passage 20a. When the negative pressure in the engine intake pipe is relatively low (close to atmospheric pressure), the pressure difference between the negative pressure chamber 24 and the atmospheric pressure chamber 28 is small, so it acts on the second diaphragm 18 to the left in FIG. The force based on this pressure difference is small, and the second diaphragm 18 is pushed to the right by the second spring 34 and is displaced (the state shown in the upper half of FIG. 1). 36 is not in contact with the second diaphragm 18, and the second diaphragm 18 and the first
The state is independent of the diaphragm 16. Therefore, only the force exerted by the first diaphragm 16 acts on the rod 40. On the other hand, since the pressure difference between the negative pressure chamber 24 and the atmospheric pressure chamber 26 is small, the force acting on the first diaphragm 16 in the right direction in Figure 81 based on this pressure difference is small compared to the force of the first spring 32. , first diaphragm 1
6 exerts a force directed to the left in FIG. 1 on the rod 40. The pushing force acting on the rod 40 decreases as the negative pressure in the negative pressure chamber 24 increases. That is, the pushing force on the rod 40 is inversely proportional to the negative pressure. Since the throttle valve 12 regulates the oil pressure in the oil passage 50, that is, the throttle pressure, according to the force acting on the spool 48 from the rod 40, the throttle pressure is affected by an increase in negative pressure as shown in the part indicated by the symbol a in FIG. The negative pressure gradually decreases to a predetermined value (400 mm/Hg in the example shown in Figure 2).
), the force generated on the first diaphragm 16 due to the negative pressure in the negative pressure chamber 24 and the force by the @1 spring 32 become equal, and the force acting on the spool 48 from the rod 40 becomes 0.
Therefore, the throttle pressure also becomes 0. On the other hand, when the negative pressure reaches this predetermined value, the force acting on the second diaphragm 18 increases due to the negative pressure in the negative pressure chamber 24, and the second diaphragm 1
8 moves to the left in FIG. 1 and comes into contact with the transmission member 36 (the state shown in the lower half of FIG. 1), that is,
The second diaphragm 18 begins to apply a pushing force to the first diaphragm 16 via the transmission member 36. from the second diaphragm 18 to the first diaphragm 16 via the transmission member 36.
The force transmitted to the pump increases as the negative pressure increases.

On the other hand, the force directed toward the right in FIG. 1 against the first diaphragm 16 due to the negative pressure in the negative pressure chamber 24 decreases as the negative pressure increases. However, since the pressure receiving area of the second diaphragm 18 is larger than the pressure receiving area of the first diaphragm 16, the pushing force of the second diaphragm 18 increases at a larger rate than the force of the first diaphragm 16 in the opposite direction. . Therefore, a force is applied to the rod 40 that increases as the negative pressure in the engine intake pipe increases.

As a result, the throttle pressure in the oil passage 50, which is regulated by the throttle valve 12, also increases in accordance with the increase in engine intake pipe negative pressure. That is, the reference numerals in FIG. 2 are already indicated. As a result, the throttle pressure in the oil passage 50 obtained by the vacuum diaphragm unit IO and the throttle valve 12 has characteristics as shown in FIG. This oil passage 50
When the throttle pressure is applied to a line pressure regulating valve (not shown) to regulate the line pressure in accordance with the throttle pressure, a line pressure having characteristics as shown in FIG. 3, for example, can be obtained. The line pressure characteristics shown in FIG. 3 correspond to the theoretically required torque capacity. This ensures that the line pressure is appropriate throughout the entire range of engine intake pipe negative pressure, eliminating any unnecessarily high pressure areas, reducing oil pump losses and, in the case of V-belt continuously variable transmissions, improving transmission efficiency. improves.

(Second Embodiment) FIG. 4 shows a second embodiment of the present invention. This second embodiment is different from the first embodiment shown in FIG. 60 was added. The other configurations are the same as in the first embodiment. As a result, the pressure adjustment value increases only in the portion of the spring 60, so the fifth
Hydraulic characteristics as shown in the figure can be obtained. In addition to this, if the negative pressure value at which the pushing force of the first diaphragm 16 becomes 0 is set to a value smaller than the negative pressure value at which the second diaphragm 18 contacts the transmission member 36 (this (can be easily adjusted by changing one or both of the two springs 34)
, the hydraulic characteristics can be as shown in FIG. That is, a region is formed on the rod 40 where no force is applied from either the first diaphragm 16 or the second diaphragm 18, and in this region a constant throttle pressure corresponding to the force of the spring 60 is obtained ( 6), thereby it is possible to obtain the throttle pressure characteristics as shown in FIG. 6, and it is also possible to obtain line pressure characteristics corresponding thereto. The line pressure characteristics in this case also approximate the required torque characteristics shown in FIG. Therefore, the same effects as in the first embodiment can be obtained. Note that the slopes of portions a and b in Figures 5 and 6 are
It can be set arbitrarily by adjusting the pressure receiving areas of the diaphragm 16 and the second diaphragm 18. It is clear that the negative pressure values at the boundary between a and C and between b and C in FIG. 6 can also be set as desired.

(Third Embodiment) FIG. 7 shows a third embodiment of the present invention, in which the throttle valve 12 of the second embodiment shown in FIG. 4 is replaced with a line pressure regulating valve 70. It is. The configuration of the vacuum diaphragm unit 10 is similar to the above embodiment.

The line pressure regulating valve 70 directs some of the oil in the oil passage 74 to which the oil discharged from the oil pump 72 is supplied to the drain boat 76.
This is a general line pressure regulating valve that regulates the oil pressure of the oil passage 74, that is, the line pressure, by discharging the line pressure.

Since the line pressure of the oil passage 74 is regulated to balance the pushing force of the rod 40, it is possible to obtain line pressure characteristics as shown in FIG. 8, for example.

(g) As described in detail of the invention, according to the present invention, the pressure regulating valve is controlled by a diaphragm unit that combines two diaphragms whose pushing force change characteristics with respect to changes in negative pressure are opposite to each other. When the negative pressure is small, the oil pressure decreases as the negative pressure increases, and when the negative pressure increases, the oil pressure increases as the negative pressure increases, making it possible to obtain an appropriate line pressure characteristic according to the required torque. be able to. This reduces oil pump loss and improves transmission efficiency in the case of a V-belt continuously variable transmission, resulting in a more efficient transmission.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention, FIG. 2 is a diagram showing throttle pressure characteristics obtained by the first embodiment, and FIG.
FIG. 4 is a diagram showing the line pressure characteristics, FIG. 4 is a diagram showing the second embodiment of the present invention, FIG. 5 is a diagram showing the throttle pressure characteristics obtained by the second embodiment, and FIG. 6 is a diagram showing the throttle pressure characteristics obtained by the WS2 embodiment. FIG. 7 is a diagram showing the third embodiment of the present invention, FIG. 8 is a diagram showing line pressure characteristics obtained by the third actual journey example, and FIG. 9 is a diagram showing another throttle pressure characteristic obtained from the engine. FIG. 2 is a diagram showing torque characteristics and conventional line pressure characteristics. 10...Diaphragm unit, 12...Throttle valve (pressure regulating valve), 16φΦ・1st diaphragm, 18・
...Second diaphragm, 24...Negative pressure chamber, 32...
First spring, 34... φ Second spring, 36-...
・Transmission member, No. 40 ・Rod.

Claims (1)

[Claims] 1. A transmission having a vacuum diaphragm unit that generates a pushing force that changes based on the applied negative pressure, and a pressure regulating valve that regulates hydraulic pressure according to the pushing force from the vacuum diaphragm unit. In the hydraulic control device, a vacuum diaphragm unit is partitioned between a first diaphragm, a second diaphragm arranged parallel to the first diaphragm and having a larger pressure receiving area, and the first diaphragm and the second diaphragm. a negative pressure chamber;
a rod that transmits the pushing force of the first diaphragm to the pressure regulating valve; a first spring that applies force to the first diaphragm from a surface on the negative pressure chamber side toward the atmospheric pressure acting side; and a first diaphragm and a second diaphragm. a transmission member capable of transmitting a pushing force between the two when the distance between the two decreases to a predetermined value;
A hydraulic control device for a transmission, comprising: a second spring that applies a force to a diaphragm from a surface on the negative pressure chamber side toward a surface on the atmospheric pressure acting side. 2. Claim 1, wherein the pressure regulating valve has a spring that always applies a force in the direction of increasing the pressure regulating value on its spool.
Hydraulic control device for the transmission described in Section 1.