JPH03134368A - Hydraulic controller of transmission - Google Patents

Abstract

PURPOSE:To reduce the driving torque of an oil pump by providing a high- pressure oil pump for continuous variable transmission mechanism, which is driven electrically, and a low-pressure oil pump for hydraulic devices, which is driven by an engine. CONSTITUTION:The high-pressure oil discharged from a high-pressure oil pump 100, which is driven electrically, is supplied to the driven pulley cylinder chamber 32 and the driving pulley cylinder chamber 20 of a continuous variable transmission, respectively, through the first regulator valve 102 and further a speed change control valve 112 so as to do continuous variable speed change. On the other hand, the low-pressure oil from a low-pressure oil pump 101, which is driven by an engine, is supplied to a torque converter 12 through the second regulator valve 104, and further to a low clutch 44, a high clutch 60, etc. through a manual valve 108 and an advance changeover valve 110. This way, the oil pump can be miniaturized as compared with the case where one high-pressure and large flow type oil pump is used.

Description

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

(b) Conventional technology As a conventional hydraulic control device for a transmission,
There is one shown in Publication No. 357.

The transmission hydraulic control device shown in Fig. 1 has one oil pump and two regulator valves. The gear ratio is continuously variable according to the oil pressure ■The oil pump is directly connected to the pulley of the belt-type continuously variable transmission mechanism, and the hydraulic clutch for forward/reverse switching is connected via the regulator valve with the higher set pressure. It is also connected to a fluid transmission device (
(fluid coupling) via the regulator valve with the lower set pressure. This is intended to supply appropriate hydraulic pressure to the pulley, hydraulic clutch, and fluid transmission device, respectively.

(C) Problems to be Solved by the Invention However, conventional hydraulic control devices for transmissions such as those described in P. require an oil pump with high pressure and a large discharge capacity. There is a problem in that the loss in the pump increases. That is, for hydraulic clutches and fluid transmissions, the oil pressure may be relatively low, but a large amount of flow is required. On the other hand, the pulley of a V-belt type continuously variable transmission mechanism requires extremely high oil pressure (30 kg/cm2 or more). In order to satisfy these two demands, the oil pump must be of a high pressure type and large in size capable of discharging a large flow rate. Therefore, the oil pump driving torque becomes extremely large. That is, in a normal transmission, the oil pump accounts for about 20 to 30% of the friction torque of the entire transmission.1. 5 for a transmission with a V-belt continuously variable transmission mechanism.
It reaches close to 0%. The present invention aims to solve these problems.

(d) Means for Solving the Problems The present invention solves the above problems by providing two oil pumps, one for high pressure and one for low pressure. That is, the present invention relates to a hydraulic control device for a transmission that has a continuously variable transmission mechanism in which the gear ratio is continuously controlled by hydraulic pressure, and a hydraulic device for power transmission or power transmission switching other than the continuously variable transmission mechanism. A high-pressure oil pump for the continuously variable transmission mechanism and a low-pressure oil pump for the hydraulic system are provided.

(E) Operation Hydraulic pressure is supplied to the continuously variable transmission mechanism from a high-pressure oil pump, while hydraulic pressure is supplied from a low-pressure oil pump to hydraulic devices such as a forward/reverse switching clutch and a fluid transmission device. A high-pressure oil pump can output high pressure but with a relatively low flow rate, while a low-pressure oil pump can output a sufficient flow rate and has a continuously variable speed mechanism. Appropriate hydraulic pressure is supplied to each of the above-mentioned hydraulic devices, and losses in the oil pump are reduced. Note that efficiency can be further improved by making the low-pressure oil pump directly driven by the engine, and by using, for example, an electromagnetic pump as the high-pressure oil pump, and operating it only when necessary.

(F) Embodiment Figures 2 and 3 show a transmission for a vehicle. A torque converter 12 is connected to an output shaft 10a of the engine 10. Torque converter 12 is pump impeller 12
a, a turbine runner 12b, and a stator 12c, and a lock-up clutch 12d that can connect or disconnect the pump impeller 12a and the turbine runner 12b. A turbine runner 12b of the torque converter 12 is connected to the drive shaft 14. A drive pulley 16 is provided on the drive shaft 14. The drive pulley 16 is a fixed conical member 18 fixed to the drive shaft 14.
and a movable conical member 22 which is disposed opposite to the fixed conical member 18 to form a V-shaped pulley groove and is movable in the axial direction of the drive shaft 14 by the hydraulic pressure acting on the drive pulley cylinder chamber 20. . Drive pulley 16
is communicatively coupled to the driven boob 926 by the V-belt 24. The driven pulley 26 includes a fixed conical member 30 fixed to the driven shaft 28 , and a V-shaped pulley groove formed by opposing the fixed conical member 30 . It consists of a movable conical member 34 that is movable in the direction. These drive pulley 16, V-belt 24, and driven pulley 26 constitute a V-belt type continuously variable transmission mechanism. The maximum gear ratio of the V-belt continuously variable transmission mechanism is:
A forward drive shaft side gear 42 and a forward output shaft side gear 4, which will be described later.
It is equal to the gear ratio between 8 and 8. Furthermore, the pressure receiving area of the driving pulley cylinder chamber 20 is the same as that of the driven pulley cylinder chamber 32.
It should be larger than the pressure receiving area of . A hollow shaft 36 is rotatably supported on the outer periphery of the drive shaft 14, and a reverse drive shaft gear 38 and a forward drive shaft gear 42 are rotatably provided on the outer periphery of the hollow shaft 36. . The forward drive shaft side gear 42 and the reverse drive shaft side gear 38 can be selectively coupled to the hollow shaft 36 so as to rotate together with the hollow shaft 36 by a synchronous meshing mechanism 52 which is a mechanical switching clutch. The drive shaft 14 and the hollow shaft 36 can be connected or disconnected from each other by a low clutch 44. A forward output shaft side gear 48 is connected to an output shaft 46 arranged parallel to the drive shaft 14 via a one-way clutch 40.
Further, a reverse output shaft side gear 50 is provided to rotate together.

The forward output shaft gear 48 is the same as the forward drive shaft gear 4 described above.
2 and is constantly engaged. The reverse output shaft side gear 50 is
It is always engaged with a reverse idler gear 56 that rotates integrally with a reverse idler shaft 54 that is rotatably provided.

The reverse idler gear 56 is the reverse drive shaft side gear 3 described above.
8 are always engaged. In addition, in FIG. 2, since it is not possible to illustrate all the members on the same cross section, the reverse idler shaft 54 and the reverse idler gear 56 are shown by broken lines, but they are actually shown in FIG. They are positioned as shown. Also, for the same reason, the center distance, gear diameter, etc. are not necessarily shown accurately in Figure 2.
Regarding these, it is necessary to refer to FIG. 3. The driven wheel 28 described above is provided with a forward driven wheel side gear 58. The driven wheel 28 and the forward driven shaft side gear 58 can be connected or disconnected from each other by a high clutch 60.

The forward driven shaft side gear 58 is the aforementioned reverse output shaft side gear 5.
0 (Note that in Fig. 2, the forward driven shaft gear 58 and the reverse output shaft gear 50 do not seem to mesh for convenience of illustration, but they are actually shown in Fig. 3). (The two are interlocked with each other.) The forward driven shaft side gear 58 and the backward output shaft side gear 50 have the same diameter.

A reduction gear 62 is provided on the output shaft 46 so as to rotate together with the output shaft 46, and the reduction gear 62 and the final gear 64 are always in mesh with each other. The final gear 64 is provided with a differential mechanism 66. That is, a pair of binion gears 68 and 70 are provided to rotate together with the final gear 64, and a pair of side gears 72 and 74 are engaged with the binion gears 68 and 70, and the side gears 72 and 74 are respectively connected to the drive shaft 76. and 78.

By releasing the low clutch 44 and the high clutch 60, the transmission of the rotational force of the drive shaft 14 to the output shaft 46 is interrupted, resulting in a neutral state.

Note that the synchronized meshing mechanism 52 may be in a neutral state, or may be in a forward position (F position) or a backward position (R position).
(The synchronous meshing mechanism 52 may be of a type without a neutral position).

In the case of running conditions that require a relatively large driving force, such as when starting or climbing, the synchronous meshing mechanism 52 is set to the F position and the low clutch 44 is engaged. high clutch 6
0 is a released state. In this state, the rotational force of the output shaft 10a of the engine 10 is transmitted to the drive shaft 14 via the torque converter 12, and further transmitted from the drive shaft 14 to the hollow shaft 36 via the engaged low clutch 44. The rotational force of the hollow shaft 36 is transmitted to the forward drive shaft side gear 42 via the synchronous meshing mechanism 52, and the forward drive shaft side gear 42
The signal is then transmitted to the forward output shaft side gear 48 that meshes with this. The forward output shaft side gear 48 is a one-way clutch 40
Since it is connected to rotate together with the output shaft 46 via the output shaft 46, rotational force is transmitted to the output shaft 46. Then,
The rotational force is transmitted to the differential mechanism 66 via the reduction gear 62 and the final gear 64, and the rotational force is distributed by the differential mechanism 66 to the drive shafts 76 and 78 to drive wheels (not shown). When transmitting rotational force as mentioned above,
The rotational force is not transmitted through the V-belt type continuously variable transmission mechanism, but is transmitted through the gear mechanism. The rotational force is increased by the reduction ratio between the forward drive shaft side gear 42 and the forward output shaft side gear 48, and thereby a large driving force can be obtained.

Next, when operating conditions are reached that require a relatively small driving force, the high clutch 60 may be engaged from the state described in L above. As a result, rotational force is transmitted via the V-belt type continuously variable transmission mechanism. That is, the rotational force of the drive shaft 14 is transmitted to the driven wheel 28 via the drive pulley 16, the V-belt 24, and the driven pulley 26, and is further transmitted to the forward driven shaft side gear 58 via the high clutch 60 in the engaged state. communicated. Since the forward driven shaft side gear 58 meshes with the backward output shaft side gear 50, rotational force is transmitted to the output shaft 46, and further rotational force is transmitted to the drive shafts 76 and 78 as in the case described above. . In this case, the output shaft 46 rotates at a higher speed than the forward output shaft side gear 48, so the one-way clutch 40 becomes idling. Therefore, the low clutch 44 can remain engaged. As mentioned above, since the rotational force is transmitted by the V-belt type continuously variable transmission mechanism, the drive pulley 1
By adjusting the V-shaped groove spacing of the driven pulley 26 and the driven pulley 26, the gear ratio can be changed continuously.

When the vehicle transmission is placed in the reverse position, the following operations are performed. That is, the synchronous meshing mechanism 52 is switched to the R position so that the reverse drive shaft side gear 38 rotates together with the hollow shaft 36, and the low clutch 44 is engaged, and the high clutch 60 is released. In this state, the rotational force of the drive shaft 14 is transmitted to the output shaft via the low clutch 44, the hollow shaft 36, the synchronous meshing mechanism 52, the reverse drive shaft gear 38, the reverse idler gear 56, and the reverse output shaft gear 50. 46. Since the reverse idler gear 56 is interposed in the power transmission path, the rotation direction of the output shaft 46 is reversed from that in the above case.

By kneading, you can move backwards.

FIG. 1 shows a hydraulic control device for controlling the speed change of the above-mentioned transmission. This hydraulic control device includes a high pressure oil pump 100.
, low pressure oil pump 101, first regulator valve 102
, accumulator 103, second regulator valve 104,
Manual valve 108, forward switching valve 110, speed change control valve 1
12 etc. These valves are connected as shown, and the torque converter 12, low clutch 4
4. The high clutch 60, the driving pulley cylinder chamber 20, and the driven pulley cylinder chamber 32 are also connected as shown.

The regulator valve 102 regulates the discharge pressure of the high-pressure oil pump 100, which is an electromagnetic pump, to a relatively high value and outputs it to the oil passage 116 as a first hydraulic pressure. Note that an accumulator 103 is provided in the discharge oil path of the high-pressure oil pump 100.

The oil passage 116 is connected to the driven pulley cylinder chamber 32. The first oil pressure has a characteristic that it increases as the gear ratio of the V-belt continuously variable transmission mechanism increases and as the throttle opening of the engine increases. The speed change control valve 112 is P
6 and PTH, the first hydraulic pressure from the oil passage 116 is reduced and supplied to the drive pulley cylinder chamber 20. In addition,
The configuration of this speed change control valve 112 is, for example, disclosed in Japanese Patent Application Laid-open No. 61-1
It is also possible to adopt a structure in which a shift command valve operated by a step motor and a gear ratio detection member for detecting the gear ratio of a continuously variable transmission are connected by a link mechanism as shown in Japanese Patent No. 05353.

The second regulator valve 104 regulates the discharge pressure of the low-pressure oil pump 101 that is directly driven by the engine 10 to a relatively low value, and supplies the second hydraulic pressure to the manual valve 108 and the torque converter 12 via the oil path 118. do. The second oil pressure has a characteristic that it increases as the throttle opening of the engine increases, and decreases as the vehicle speed increases. The manual valve 108 switches the output state of hydraulic pressure from the oil passage 118 according to the position of a select lever operated by the driver. In the D range, oil pressure is output to the oil passage 120. The forward switching valve 110 is switched depending on the balance between the governor pressure P6 corresponding to the vehicle speed and the throttle pressure PTH corresponding to the engine load, and supplies the hydraulic pressure in the oil passage 120 to the low clutch 44 or the high clutch 60.

Next, the operation of this embodiment will be explained. When the vehicle speed is low, such as when starting, the forward switching valve 110 supplies hydraulic pressure only to the low clutch 44 and does not supply hydraulic pressure to the high clutch 60. Therefore, the low clutch 44 is engaged,
As described above, the rotational force is transmitted via the gear transmission path.

As described above, operation is performed via the gear transmission path, and when a predetermined operating state is reached, such as when the vehicle speed increases, the forward switching valve 110 is switched and hydraulic pressure is supplied to the oil passage 124. Therefore, the high clutch 60 is engaged and the gear transmission path is switched to the V-belt transmission path as described above. Note that at this point, the speed change control valve 112 is connected to the drive pulley cylinder chamber 2.
The oil pressure supplied to the V-belt type continuously variable transmission mechanism is set to the lowest state, and the gear ratio of the V-belt type continuously variable transmission mechanism is a predetermined maximum gear ratio (this is equal to the gear ratio of gears 42 and 48).

From this state, when the hydraulic pressure supplied to the drive pulley cylinder chamber 20 increases due to the action of the speed change control valve 112, the speed change ratio gradually changes to the smaller side. From now on, shift control valve 1
12, speed change control is performed between the maximum speed ratio and the minimum speed ratio of the V-belt type continuously variable transmission mechanism.

As described above, the low pressure oil pump 101 is directly driven by the engine, while the crystal pressure oil pump 100 is an electromagnetic pump that operates using a battery as a power source. Therefore, the high pressure oil pump 100 can control its operation so as to discharge the minimum oil pressure and flow rate required for the continuously variable transmission mechanism, while the low pressure oil pump 101 can control the torque converter 12, the high clutch 60, and the low pressure oil pump 101. The capacity may be sufficient to ensure the oil pressure and flow rate required by the clutch 44 and the like. As a result, both oil pumps 100 and 101
The operation of the oil pump becomes more efficient, and the overall oil pump drive torque is reduced. Furthermore, since an accumulator 103 is provided in the oil passage on the high pressure oil pump 100 side,
When the continuously variable transmission mechanism does not require a flow rate, such as when driving at a constant speed and a constant gear ratio, the high-pressure oil pump 10 is used.
0 operation can be stopped. Further, as shown in FIG. 4 or FIG. 5, the high pressure oil pump 100 can be placed close to the strainer 200 in the oil reservoir 198, and the low pressure oil pump 101 and the high pressure oil pump 100 The strainer 200 can be shared.

Although this embodiment is a so-called hybrid type transmission that is equipped with a gear mechanism with a gear ratio larger than the maximum gear ratio of the V-belt continuously variable transmission mechanism, it is basically a V-belt continuously variable transmission mechanism. The present invention can be similarly applied to a transmission made up of only two parts. Further, as the continuously variable transmission mechanism, it is also possible to employ a friction wheel type continuously variable transmission mechanism other than the V-belt type continuously variable transmission mechanism.

(g) As described in detail, according to the present invention, a high-pressure oil pump is provided for the continuously variable transmission mechanism, and a low-pressure oil pump is provided for other hydraulic devices. High pressure/
Compared to the case where a large flow rate type oil pump is used, it is possible to obtain the effect that the oil pump can be made smaller and the oil pump drive torque can be reduced to improve efficiency.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a hydraulic control device for a transmission according to the present invention;
Figure 2 is a frame diagram of the transmission, Figure 3 is a diagram showing the positional relationship of the shafts of the transmission shown in Figure 2, Figure 4 is a diagram showing the arrangement of the high pressure oil pump, and Figure 5 is a diagram showing the high pressure oil pump. FIG. 3 is a diagram showing another arrangement of the oil pump. 20... Drive pulley cylinder chamber, 32... Driven pulley cylinder chamber, 44... Low clutch, 60... High clutch, 100... High pressure oil pump, 101
...Low pressure oil pump.

Claims (1)

[Scope of Claims] 1. A hydraulic control device for a transmission that includes a continuously variable transmission mechanism in which the gear ratio is continuously controlled by hydraulic pressure, and a hydraulic device for power transmission or power transmission switching other than this mechanism, A hydraulic control device for a transmission, comprising a high-pressure oil pump for a continuously variable transmission mechanism and a low-pressure oil pump for the hydraulic system. 2. The hydraulic control system for a transmission according to claim 1, wherein the high pressure oil pump is an electrically driven pump, and the low pressure oil pump is a pump directly driven by the engine. 3. The hydraulic control system for a transmission according to claim 1 or 2, wherein an accumulator is provided in the oil passage connected to the high-pressure oil pump.