JPS62151659A - Switching control device of speed change gear - Google Patents

Abstract

PURPOSE:To overcome disadvantages such as blow-up of an engine and forcible release of a dog clutch by interlocking a spool of a switching control valve with a fork of a dog clutch connected at the time of direct drive. CONSTITUTION:When a solenoid valve 103 is turned on, oil pressure is conducted to a left chamber 91 of a piston 90, a fork is moved to the right through a rod 94 to switch a dog clutch to a direct drive position. Interlocking with the operation, a spool 82 of a switching control valve 80 is moved to the right, so that a port 86 to a clutch control valve 70 is drained. Accordingly, only after direct coupling a clutch is disconnected so that blow-up of an engine is not caused. Subsequently, when the solenoid valve 103 is turned off for switching to belt drive, the spool 82 is moved to the left to conduct oil pressure to the clutch control valve 70, and oil pressure is not supplied to the hydraulic piston 90 simultaneously, so that the fork is urged in the direction of non-direct coupling only by spring 95. Thus, forcible release of the dog clut h is not caused.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a transmission switching control device, and more particularly to a transmission switching control device.

The present invention relates to a device for smoothly switching between direct drive and continuously variable speed drive in a transmission in which a direct drive path and a continuously variable speed path are provided in parallel between output shafts.

Conventional technology and its problems Various types of continuously variable transmissions have been known in the past, such as V-held type continuously variable transmissions and toroidal type continuously variable transmissions.
In either case, there is a problem in that the power transmission efficiency during continuously variable speed driving is about 10 to 15% inferior to the transmission efficiency of gears, chains, etc. Therefore, as described in Japanese Patent Publication No. 57-23136, a direct drive path having a fixed transmission ratio between the input shaft and the output shaft and a continuously variable transmission path including a Held type continuously variable transmission are provided in parallel. At the same time, a clutch is provided in each of the direct drive path and the continuously variable transmission path, and by driving through the stepless variable speed path in the low speed ratio range and driving through the direct drive path in the high speed ratio range, A device with improved power transmission efficiency has been proposed.

By the way, since running in a high-speed ratio state generally occupies most of the running time, the engagement time of the clutch provided in the direct drive path is inevitably long. However, if a normal wet clutch is used as a clutch, high oil pressure must be continuously supplied to this clutch during direct drive, resulting in increased oil pump discharge loss and f1! , 't is a problem.

Therefore, if a dog clutch is used as a clutch in the direct drive path, 4. 4. There is no need to keep applying high oil pressure when the oil is overflowing, so the oil pump's discharge loss can be reduced. However, in the case of a dog clutch, it is difficult to perform smooth switching like a wet clutch due to the sliding resistance of the spline teeth and head butt, and when switching from continuously variable speed drive to direct drive, the engine power is not transferred to either path. There is a situation in which the transmission is not carried out, which may cause the engine to rev up. Additionally, when it is necessary to quickly shift to a lower speed ratio, such as during kickdown, the dog clutch must be forcibly pulled out to switch from direct drive to continuously variable speed drive, but this is not possible under load. If the dog clutch is forcibly removed, the spline teeth will wear out, shortening the life of the dog clutch.

Purpose of the Invention The present invention has been made in view of the above problems, and its purpose is to prevent the engine from revving up or forcefully disengaging the dog clutch when switching between direct drive and continuously variable speed drive, and to ensure smooth switching. An object of the present invention is to provide a transmission switching control device that can perform the following steps.

Structure of the Invention In order to achieve the above object, the present invention provides a direct connection drive path having a fixed transmission ratio and a continuously variable transmission path that performs continuously variable transmission in parallel between an input shaft and an output shaft. In a transmission in which a drive path is provided with a dog clutch that is engaged during direct drive, and a continuously variable transmission path is provided with a power intermittent clutch that is disconnected during direct drive, a hydraulic piston that operates a fork of the dog clutch; It is equipped with a clutch control valve that connects and disconnects the power intermittent clutch, and a switching control valve that switches the hydraulic pressure to the hydraulic piston and clutch control (a) valve by signal hydraulic pressure when directly connected, and the spool of the switching control valve 1b and the switching control valve The spool is engaged with the fork so that it can move relative to the fork for a fixed stroke, and a spring is interposed between the spool and the fork, and when the spool is directly connected, the spool moves to a position close to the fork, directly connecting the hydraulic pressure to the hydraulic piston. After switching to the direction, the hydraulic pressure to the clutch control valve is switched to the blocking direction in conjunction with the fork, and when the spool is not directly connected, the spool moves to a position away from the fork and the hydraulic pressure to the clutch control valve is switched to the coupling direction. , which works in conjunction with the fork to switch the hydraulic pressure to the hydraulic piston in a direction that is not directly connected.

In other words, by interlocking the switching control valve spool with the fork, and by having the spool switch the oil path to the hydraulic piston and clutch control valve in a fixed order, engine revving and dog clutch/7ch problems can be avoided. This prevents

DESCRIPTION OF EMBODIMENTS FIG. 1 shows an example of a transmission according to the present invention, in which a fluid coupling cover 2 is coupled to an end of a crankshaft 1 of an engine, and a fluid coupling is configured inside the fluid coupling cover 2. A pump 3, a turbine 4, and a centrifugal lock-up clutch 5 are rotatably housed.

The input shaft 6 is connected to the turbine 4 and the lock-up clutch 5, and a direct connection drive gear 7 constituting a direct connection drive path is rotatably inserted into the input shaft 6. 6 means 14uA due to dog clutch 8
be done. 8 includes a spline hub 6a fixed to the input shaft 6, a spline m1a formed integrally with the direct coupling drive gear 7, and these splines 6a, ? A and a switching sleeve 8a that connects and blocks the switching sleeve 8a, and the switching sleeve 8a is actuated in the axial direction by the fork 33.

An external gear 9 is fixed to the end of the input shaft 6, and this external gear 9 is connected to the drive shaft 11 of the V-belt type gear transmission lO.
It meshes with an internal gear 12 fixed to the input shaft 12 to reduce the driving force of the input shaft 6 and transmit it to the drive shaft II. ■The belt-type continuously variable transmission 10 includes a drive-side pulley 1 provided on a drive shaft 11.
3, a driven pulley 15 provided on the driven shaft 14, and a belt 16 wound between both pulleys. The drive pulley 13 has a fixed sheave 13a and a movable sheave 13b, and a thrust generating device 3 provided behind the movable sheave 13b.
4 applies a thrust commensurate with the input torque to the movable sheave 13b. As the thrust generating device 34, for example, a torque cam device that generates a thrust corresponding to input torque, a hydraulic servo device that generates a thrust corresponding to input torque using line pressure, or the like can be used. On the other hand, driven pulley 1
Similarly to the drive pulley 13, the sheave 5 has a fixed sheave 15a and a movable sheave 15b, and a hydraulic chamber 18 for speed ratio control is provided behind the movable sheave 15b. The hydraulic pressure to this hydraulic chamber 18 is controlled by a hydraulic control device described later.

A hollow shaft 19 is rotatably fitted around the outer periphery of the driven shaft 14, and the driven shaft 14 and the hollow shaft 19 are connected to each other by a power intermittent clutch 20 consisting of a wet type clutch. The hydraulic pressure to this clutch 20 is also controlled by a hydraulic control device which will be described later, and the driven shaft 14 and the hollow shaft 19 are connected during held drive (excluding when switching forward/backward or when suddenly decelerating).
Shuts off during direct drive. The hollow shaft 19 has a forward gear 2.
1 and a reverse gear 22 are rotatably inserted, and either the forward gear 21 or the reverse gear 22 is connected to the hollow shaft 19 by a forward/reverse switching sleeve 23 . A reverse idle gear 25 that meshes with the reverse gear 22 and another reverse idle gear 26 are fixed to a reverse idle shaft 24 arranged parallel to the driven shaft 14 . A counter shaft 27 is also arranged parallel to the driven shaft 14, and a counter gear 28 and a final reduction gear 29 are fixed to this counter shaft 27. The counter gear 28 is the direct connection drive gear 7, the forward gear 21, and the reverse idle gear 2.
6 and also serves as a direct-coupling driven gear.

The final reduction gear 29 meshes with a ring gear 31 of a differential device 30 and transmits power to an output shaft 32.

In the transmission with the above configuration, the dog clutch 8°, the drive gear 7 for direct connection, the counter gear 2, and the final reduction gear 29. The differential device 30 forms a direct drive path, while the external gear 9. Internal gear 12. V-belt ceremonial gear shifting section 10. Clutch 20, forward gear 21. Counter gear 28. Final reduction gear 29. Differential equipment Z30
forms a belt driven J path (continuously variable speed path).

The transmission ratio between the human power shaft 6 and the output shaft 32 in the direct drive path is set to be slightly lower than the maximum speed ratio between the input shaft 6 and the output shaft 32 in the heald drive path.

Fig. 2 shows a hydraulic control device, 40 is a pulley control valve, 50 is a shift down control valve, 60 is a Scottle valve, 70 is a flange control valve, 80 is a switching control valve, 90 is a hydraulic piston, and 100 is a micro Control circuits 101, 102, and 103, such as computers, are the first and second control circuits, respectively. Second. The third solenoid valve 104 is an oil passage through which line pressure is introduced from a hydraulic source.

The pulley control valve 40 has a spool 42 biased leftward by a spring 41.
A first solenoid valve 101 is installed in the right end chamber 43 that accommodates the
The solenoid pressure is derived from. On both sides of the port 44 communicating with the hydraulic chamber 18 of the driven pulley 15, a port 45 to which line pressure is introduced and a drain port 46 are formed.

A port 44 communicating with the hydraulic chamber 18 is connected to a spool 42.
It communicates with the left end chamber 47 through a communication hole 42a formed inside the hydraulic chamber 18, so that the hydraulic pressure in the hydraulic chamber 18 is a hydraulic pressure balanced with the sum of the solenoid pressure of the first solenoid valve 101 and the spring force of the spring 41. controlled by.

The shift down control valve 50 has a spool 52 biased leftward by a spring 5■, and the signal hydraulic pressure of the second solenoid valve 102, which is turned ON during kickdown and sudden deceleration, is guided to the left end chamber 53. There is. The downshift control valve 50 includes a boat 54 that communicates with the boat 45 of the pulley control valve 40, and a switching control valve 8.
0, a boat 56 that communicates with the clutch control valve 70, and a boat 57 that communicates with the throttle valve 60.
When 02 is ○FF (signal oil pressure is 0FF), the spool 52 is at the left end position as shown in the figure, and the boats 55 and 5
6 communicates with each other to apply line pressure to the clutch control valve 70. Note that at this time, communication between the boats 54 and 55 leading to the pulley control valve 40 is cut off, but the line pressure is passed through the orifice 58 to the pulley control valve 40.
It is constantly guided by boat 45. On the other hand, when the second solenoid valve 102 is turned on (the signal oil pressure is turned on), the spool 52 moves to the right, and the boats 54 and 55 communicate with each other to supply line pressure to the pulley control valve 40, while the boat 55 and 56 is cut off.

The throttle valve 60 is linked to the accelerator pedal, and when the throttle opening is fully closed or close to fully closed, the spool 62 is at the left end position by the spring 61, and the boat 63 leading to the downshift control valve 5° is closed. Also, sloth.

When the torque opening degree is opened, the spool 62 moves to the right, the boats 63 and 64 communicate with each other, and line pressure is guided to the downshift control valve 50.

The clutch control valve 70 has a boat 71 at the right end that communicates with the boat 56 of the downshift control valve 50,
The spool 72 moves to the left against the spring 73 due to the hydraulic pressure acting on the boat 71, and a boat 74 to which line pressure is supplied and a boat 75 leading to the clutch 20 are moved.
and the drain port 76 are selectively switched. That is, when hydraulic pressure is not acting on the rightmost boat 71, the spool 72 is at the rightmost position, the boat 74 is closed, the boats 75 and 76 are in communication, and the hydraulic pressure in the clutch 20 is drained, causing the clutch 20 to be disengaged. ing. On the other hand, when hydraulic pressure acts on the boat 71 on the right end, the spool 72 moves to the left and the boats 74 and 75 communicate with each other, and the hydraulic pressure is guided to the clutch 20.
It is a system that connects.

The switching control valve 80 has a spool 82 biased to the left by a spring 81 whose one end is in contact with the fork 33 of the dog clutch 8, and the right end of the spool 82 is inserted into the hole 33a of the fork 33. The spool 82 can be moved relative to the fork 33 by a fixed stroke due to the stepped portion 82a and the stopper 82b provided on the spool 82. 6f for the switching control valve 80
[Lil boats 83 to 88 are formed, and the boat 83 at the left end is guided by the signal hydraulic pressure of the third solenoid valve 103 that is turned ON during direct drive, and the boat 84 at the right end is connected to the left chamber of the hydraulic piston 90. Connect to 91, boat 8
Line pressure is introduced to 5, and the boat 86 is connected to the boat 4 of the pulley control valve 40 via the downshift control valve 50.
5 or the right end port 71 of the clutch control valve 70, the boat 87 communicates with the right chamber 92 of the hydraulic piston 90, and the boat 88 serves as a drain boat.

The hydraulic piston 90 has a piston member 93 that is movable by hydraulic pressure acting on left and right chambers 91 and 92. A rod 94 is connected to this piston member 93, and the fork 33 of the dog clutch 8 is connected to the middle of the rod 94. has been done. Further, a spring 95 is housed in the right chamber 92, and constantly urges the piston member 93 to the left, that is, in the direction of non-direct connection.

The control circuit 100 receives the input rotation speed of the input/sleeve 6, the output rotation speed (vehicle speed) of the output shaft 32, a brake signal, a throttle opening signal, a position control signal, etc. 1 to 3rd solenoid valve 101 to 1
It is designed to control 03. For example, a duty control signal is output to the first solenoid valve 101 in accordance with the running state, and a duty control signal is output to the hydraulic chamber 1 via the boolean control valve 40.
8 hydraulic pressure is finely controlled. Further, an ON signal is output to the second solenoid valve 102 during kickdown and sudden deceleration, operating the downshift control valve 50 to achieve a quick shift to a low speed ratio.

Further, an ON signal is outputted to the third solenoid valve 103 during direct drive, and the switching control valve 80 is operated to perform smooth switching control without engine revving.

Next, the operation of the switching control valve 80 will be explained according to FIGS. 2 to 5.

FIG. 2 shows the belt drive state, and since the third solenoid valve 103 is OFF, the spool 82 of the switching control valve 80 is at the left end position, and the line pressure supplied to the port 85 is applied to the right chamber of the hydraulic piston 90. 92 to bias the fork 33 in the direction of non-direct connection, and at the same time, the line pressure is led from the port 86 to the right end chamber 71 of the clutch control valve 70 via the shift down control valve 50, thereby engaging the clutch 20. There is.

FIG. 3 shows the moment when the third solenoid valve 103 is turned on to switch from heald drive to direct drive. Third
When the solenoid valve 103 is turned on, a signal hydraulic pressure is guided to the boat 83 at the left end of the switching control valve 80, and the stepped portion 82a of the spool 82 moves to the right until it comes into contact with the fork 33 by this signal hydraulic pressure. In this state, the boat 87 leading to the right chamber 92 of the hydraulic piston 90 is drained, and the hydraulic pressure is guided to the boat 84 leading to the left chamber 91, but the boat 84 is provided with a protrusion 84a to restrict the flow rate. Although the fork 33 is biased to the right (direction of direct connection), the dog clutch 8 has not yet been switched to the direct connection state. Further, since oil pressure is still being introduced to the port 86 leading to the clutch control valve 70, the clutch 20 remains engaged.

FIG. 4 shows a state in which the third solenoid valve 103 is turned on and a certain period of time has elapsed, and the state has been completely switched to direct drive. That is, since the hydraulic pressure is continuously introduced into the left chamber 91 of the hydraulic piston 90 from the state shown in FIG. 3, the fork 33 is pushed to the right, and eventually the dog club and 7-chi 8 are switched to the direct connection position. Since the spool 82 also moves to the right in conjunction with the fork 33, the port 86 communicating with the clutch control valve 70 is drained, and the clutch 20 is disconnected. In this way, the clutch 20 is not disconnected until after the dog clutch 8 is switched to the direct connection position, so there is no risk of the engine revving up.

FIG. 5 shows the moment when the third solenoid valve 103 is turned off to switch from direct drive to belt drive. That is, when the signal oil pressure of the boat 83 on the left end is turned off, the spool 82 quickly moves to the left by the spring force of the spring 81 until the stopper 82b comes into contact with the back surface of the fork 33, and the port 86 is opened and the clutch control valve 70 is opened. The hydraulic pressure is introduced and the clutch 20 is engaged. In this state, both the boats 84 and 87 communicating with the left and right chambers 91 and 92 of the hydraulic piston 90 are drained, so the fork 33 is urged in the non-directly connected direction only by the spring force of the spring 95. As the clutch 20 starts to engage, power is transmitted to the belt drive path, but since the speed ratio of the belt drive path is on the higher speed side than the direct coupling transmission ratio, it is a dog club.

Output side spline tooth 7a from input side sleeve 8a
rotates faster, and even with a weak spring load of the spring 95, the dosing latch 8 starts to be released easily. As a result, the fork 33 and the spool 82 move to the left in conjunction with each other, and the hydraulic pressure is eventually led to the port 87 leading to the right chamber 92.
The fork 33 quickly moves to the left (in the direction of non-direct connection) by the spring force of the spring 95 and the hydraulic load, disengages the dog clutch 8, and returns to the state shown in FIG. in this way,
Dog clutch 8 when switching from direct drive to belt drive
Since the dog clutch 8 is removed without being forced out, wear on the spline teeth of the dog clutch 8 can be prevented.

In the above embodiment, in order to prevent the dog clutch 8 from being forcibly disengaged when switching from direct drive to continuously variable speed drive (see Fig. 5), the dog clutch 8 is initially moved to a certain extent by only the spring force of the spring 95). After removing the water, the boat 87 is opened to guide the hydraulic pressure to the right ventricle 92. However, the present invention is not limited to this. For example, the spring 95 may be omitted, the pressure receiving area of the right ventricle 92 may be made smaller, and the hydraulic pressure may be introduced to the right ventricle 92. A method of limiting the force of the fork 33 when guided to such an extent that the dog clutch 8 cannot be forcibly removed, and a method of releasing the dog clutch 8 only by the spring load of the spring 95 without introducing hydraulic pressure to the right chamber 92. etc. can also be used.

In addition, the continuously variable transmission of the present invention is not limited to the belt type, but also the toroidal type continuously variable transmission (for example, JP-A-58-5
4262) can be used, and the direct drive path is not limited to the gear train as in the above embodiment, but a chain or a toothed belt may also be used.

Furthermore, in addition to the solenoid valve 103, as means for generating signal hydraulic pressure during direct coupling, another valve is provided which mechanically detects the pulley ratio and generates signal hydraulic pressure when the pulley ratio reaches the direct coupling transmission ratio. Good too.

Effects of the Invention As is clear from the above explanation, according to the present invention, the spool of the switching control valve is linked with the fork, and the oil passages to the hydraulic piston and the clutch control valve are switched in a fixed order, that is, switching to direct drive. Sometimes, after switching the hydraulic piston to the direct coupling direction, the hydraulic pressure to the clutch control valve is cut off, and when switching to continuously variable speed drive, the hydraulic piston is operated in the non-coupling direction after introducing the hydraulic pressure to the clutch control valve. This eliminates problems such as engine revving and forced release of the dog clutch, and enables smooth switching.

[Brief explanation of drawings]

FIG. 1 is a skeleton diagram of an example of a transmission according to the present invention;
FIG. 2 is a circuit diagram of the hydraulic control device, and FIGS. 3 to 5 are explanatory diagrams of the operation of the switching control valve. 6... Input shaft, 7... Direct drive gear, 8... Dog clutch, 10... V-belt type continuously variable transmission, 2
0...Power intermittent clutch, 28...Counter gear (
Direct connection driven gear), 32... Output shaft, 33... Fork, 70... Clutch control valve, 80... Switching control valve, 81... Spring, 82... Spool, 82a...・Stepped portion, 82b...Stopper, 90・
...Hydraulic piston, 100...Control circuit, 103...
・Solenoid valve. Applicant Daihatsu Motor Co., Ltd. Agent Patent Attorney Hidetaka Tsutsui Figure 1 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] (1) A direct drive path with a fixed transmission ratio and a continuously variable transmission path that performs continuously variable speed are provided in parallel between the input shaft and the output shaft, and a dog clutch is connected to the direct drive path during direct drive. A transmission comprising a continuously variable transmission path including a power intermittent clutch that is disconnected during direct drive, a hydraulic piston that operates a fork of the dog clutch, and a clutch control valve that engages and engages the power intermittent clutch; a switching control valve that switches hydraulic pressure to the hydraulic piston and the clutch control valve by a signal hydraulic pressure when directly connected; A spring is interposed between the fork and the spool, and when the spool is directly coupled, the spool moves to a position close to the fork, switches the hydraulic pressure to the hydraulic piston to the direct coupled direction, and then works in conjunction with the fork to transfer the hydraulic pressure to the clutch control valve. When not directly connected, the spool moves to a position away from the fork and switches the hydraulic pressure to the clutch control valve to the connected direction, and then works in conjunction with the fork to switch the hydraulic pressure to the hydraulic piston to the non-directly connected direction. A transmission switching control device characterized by: