JPS6263259A - Direct-coupling control method for transmission - Google Patents

Abstract

PURPOSE:To quickly engage a dog clutch, by reciprocatively controlling a speed change ratio in belt driving with reference to a direct-coupling gear ratio as a target value, and sliding spline teeth forwardly and rearwardly. CONSTITUTION:A speed change ratio i in belt driving is reciprocatively controlled with reference to a direct-coupling gear ratio i' as a target value under the condition where a dog clutch 8 is urged in a direct-coupled direction. Accordingly, output spline teeth 7a are slided forwardly and rearwardly relative to an input sleeve 8a of the dog clutch 8, and the spline teeth under a head abutment condition are meshed at a moment. Thus, the dog clutch 8 may be easily coupled and also quickly meshed.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a direct control method for a transmission, and more specifically, a method for directly controlling a transmission.

The present invention relates to a control method for smoothly switching from belt drive to direct drive in a transmission in which a direct drive path and a belt drive path are provided in parallel between output shafts.

Prior art and its problems In general, there is a problem that the power transmission efficiency of belt drive is inferior to that of gear drive.
As described in Publication No. 4058, a direct drive path including a direct gear train and a belt drive path including a belt type continuously variable transmission are provided in parallel between the input shaft and the output shaft, and The drive path and the belt drive path are each provided with a power intermittent means, and power is transmitted through the belt drive path in the low speed ratio range, and through the direct drive path in the high speed ratio range, so that the power in the high speed ratio range is transmitted. Belt belts with improved transmission efficiency and belt life have been proposed.

In the above case, a hydraulic clutch or a dosog clutch can be considered as a means for connecting and disconnecting the power of the direct drive path, but in the case of a hydraulic clutch, a large hydraulic pressure must be applied continuously during engagement, resulting in a large loss of energy, which reduces the running time. It is not suitable for power intermittent use during high speed driving (during direct drive), which is the majority of the time. On the other hand, a dog clutch has the advantage of being able to eliminate the problem described in item 1 above, but when switching from belt drive to direct drive, there is a risk that the spline teeth of the dog clutch may cause head butt. If the dog clutch is in a head-butting state, it will cause a shift failure, resulting in a delay in switching to direct drive, or in the worst case, it will not be possible to switch to direct drive.

Purpose of the Invention The present invention has been made in view of such conventional problems.
The purpose is to provide a direct-coupling control method for a transmission that can eliminate shift failures caused by dog clutch head butting and ensure reliable direct-coupling switching when switching from belt drive to direct-coupling drive.

Structure of the Invention In order to achieve the above object, the present invention provides a system in which a directly connected drive path including a directly connected gear train and a belt drive path including a belt type continuously variable transmission section are connected in parallel between an input shaft and an output shaft. A transmission comprising: a dog clutch that is engaged during direct coupling drive in the middle of the direct coupling drive path; and a power intermittent clutch that is coupled during belt drive in the middle of the belt drive path,
The gear ratio of the direct drive path is set to a lower speed side than the maximum speed ratio of the belt drive path, and when switching from belt drive to direct drive, the gear ratio of the belt drive path is reciprocated with the direct drive gear ratio as a target value, When the dog clutch operates to the direct connection position, this is detected by the direct connection switch and the reciprocating control described above is terminated.

In other words, ■Since the pulley ratio of the belt-type continuously variable transmission section is constantly changing, by utilizing this property and reciprocatingly controlling the gear ratio of the belt drive path using the direct gear ratio as the target value, the head of the dog clutch can be adjusted. The reciprocating control described above is terminated after the collision is prevented and the direct coupling switch detects that the dog clutch is engaged, thereby ensuring reliable switching to direct coupling drive.

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 coupled to the turbine 4 and the lock-up clutch 5, and a direct coupling gear 7 constituting a direct coupling gear train is rotatably inserted into the input shaft 6. The shaft 6 is selectively connected to the shaft 6 by a dog clutch 8. The dog clutch 8 is composed of a spline hub 6a fixed to the input shaft 6, spline teeth 7a integrally formed with the direct coupling gear 7, and a switching sleeve 8a spline-engaged with these splines 6a, 7a. The switching sleeve 8a is actuated in the axial direction via the shift fork 32 by an actuator 90, which will be described later.

A direct connection switch 35 is provided on the side of the shift fork 32, and is turned on when the shift fork 32 moves to the direct connection position.

An external gear 9 is fixed to the end of the input shaft 6, and this external gear 9 meshes with an internal gear 12 fixed to the primary shaft 11 of the belt heating stage transmission section 10. The driving force is decelerated and transmitted to the primary shaft 11. ■The belt-type continuously variable transmission unit IO has a driving pulley 13 provided on the secondary shaft 11, a driven pulley 15 provided on the secondary shaft 14, and a belt 16 wound between both pulleys. ing. The drive pulley 13 has a fixed sheave 13a and a movable sheave 13b, and a thrust force corresponding to the input torque is applied to the movable sheave 13b by a thrust generating torque cam 33 and a torsion spring 34 provided behind the movable sheave 13b. There is.

On the other hand, the driven pulley 15 also has a fixed sheave 15a and a movable sheave 15b, similar to the drive side boolean I713.
A hydraulic chamber 18 is provided for axially operating the cylinder.

The hydraulic pressure to this hydraulic chamber 18 is controlled by a hydraulic control device described later.

A driven shaft 19 is rotatably inserted around the outer periphery of the secondary shaft 14 , and the secondary shaft 14 and the driven shaft 19 are connected to each other by a power intermittent clutch 20 . This clutch 20 is also operated by a hydraulic control device to be described later, and connects the secondary shaft 14 and the driven shaft 19 during belt drive, and disconnects it during direct drive. A forward gear 21 and a reverse gear 22 are rotatably fitted onto the driven shaft 19, and either the forward gear 21 or the reverse gear 22 is connected to the driven shaft 19 by a forward/reverse switching device 23. .

The reverse idle shaft 24 is disposed parallel to the driven shaft 19, and a reverse idle gear 25 that meshes with the reverse gear 22 and a reverse idle gear 26 are fixed to this shaft 24.

The counter shaft 27 is also arranged parallel to the driven shaft 19,
A counter gear 28 that also serves as a direct coupling gear that simultaneously meshes with the direct coupling gear 7, the forward gear 21, and the reverse idle gear 26, and two final reduction gears are fixed to the counter shaft 27. 29 meshes with the differential device 30 and transmits power to the output shaft 31.

FIG. 2 shows a hydraulic control device for controlling the driven pulley 15, dog clutch 8, and power intermittent clutch 20, where 40 is a pulley control valve, 50 is a kickdown control valve, 60 is a throttle valve, and 70 is a pulley control valve. Clutch control valve, 80 is a lock-up control valve, 90 is an actuator, 100 is a control circuit such as a microcomputer, 101, 102, 103 are the first. The second and third solenoid valves 104 are oil passages 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
Hydraulic pressure (solenoid pressure) is guided by turning ON and OFF.

A port 45 to which line pressure is introduced and a drain boat 46 are formed on both sides of a port 44 communicating with the hydraulic chamber 18 of the driven pulley 15. The port 44 that communicates with the hydraulic chamber 18 communicates with the left end chamber 47 via a communication hole 42 a formed inside the spool 42 .
When FF (solenoid pressure 0FF), the hydraulic pressure is controlled to be balanced with the spring force of the spring 41, and when the first solenoid valve 101 is ON (solenoid pressure ON), the hydraulic pressure is controlled to be balanced with the sum of the spring force of the spring 41 and the solenoid pressure. be done. Therefore, the first solenoid valve 10
When 1 is OFF, the oil pressure in the oil pressure chamber 18 is low and controlled to the high speed ratio side, and when it is ON, the oil pressure in the oil pressure chamber 18 is high and controlled to the low speed ratio side.

The kickdown control valve 50 also serves as a coastdown control valve, and has a spool 52 biased leftward by a spring 51, and a second solenoid valve 102 in the left end chamber 53 is turned on.

Hydraulic pressure (solenoid pressure) controlled by OFF is introduced. The kickdown control valve 50 includes a port 54 that communicates with the port 45 of the pulley control valve 40, a port 55 that communicates with the lockup control valve 80, a port 56 that communicates with the clutch control valve 70, and a port 56 that communicates with the throttle valve 60. When the second solenoid valve 102 is turned off (solenoid pressure is 0FF), the spool 52 is connected as shown in the figure.
is at the left end position, ports 55 and 56 are in communication, and line pressure is applied to the clutch control valve 70. Note that at this time, communication between ports 54 and 55 leading to the pulley control valve 40 is cut off, but since the line pressure is acting on the port 45 of the pulley control valve 40 via the orifice 58, the pressure in the hydraulic chamber 18 is Oil pressure never goes to zero. On the other hand, when the second solenoid valve 102 is turned on (the solenoid pressure is turned on), the spool 52 moves to the right, ports 54 and 55 communicate with each other, and line pressure is supplied 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 moved by a spring 61 as shown by the dashed line.
is in the leftmost position, and the boat 63 leading to the kickdown control valve 50 is closed. Further, when the throttle opening is opened, the spool 62 moves to the right and the boats 63 and 64 communicate with each other, and the line pressure is increased to the kickdown control valve 5.
It leads to 0.

The clutch control pulp 70 has a boat 71 at the right end that communicates with the port 56 of the kickdown control valve 50,
The spool 72 moves to the left against the spring 73 by the hydraulic pressure acting on the port 71, and the port 75 leads to the boat 74 to which line pressure is supplied and the clutch 20.
and the drain port 76 are selectively switched. That is, when hydraulic pressure is not applied to the right-most port 71, the spool 72 is at the right-most position, the boat 74 is closed, the boats 75 and 76 are in communication, and the hydraulic pressure in the clutch 20 is drained and the clutch 20 is disengaged. . 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 lock-up control valve 80 is a pulp that controls the actuator 90, and has a spool 82 biased to the left by a spring 81, and is located in the left end chamber 83 and is controlled by turning on and off a third solenoid valve 103. Hydraulic pressure (solenoid pressure) is guided. Five ports 84 to 88 are formed in the lock-up control valve 80, the rightmost port 84 communicates with the left chamber 91 of the actuator 90, line pressure is introduced to the port 85,
Port 86 is port 55 of kickdown control valve 50
The port 87 communicates with the right ventricle 92 of the actuator 90.
The boat 88 on the left end is a drain boat. Note that the shift fork 32 is located at the right end of the lock-up control valve 80. When the third solenoid valve 103 is OFF (the solenoid pressure is OFF), the spool 82 is at the left end position as shown in the figure, the l boats 85, 86, and 87 are in communication, and the line pressure is transferred to the right chamber 92 of the actuator 90 for kickdown. and the boat 55 of the control valve 50. On the other hand, when the third solenoid valve 103 is turned on (the solenoid pressure is turned on), the spool 82 moves to the right, ports 84 and 85 communicate with each other, supplying line pressure to the left chamber 91 of the actuator 90, and the spool 82 moves to the right. When the spool 82 moves to the right, the spool 82 comes into contact with the shift fork 32 and moves to the right as a unit, and the boat 86 is also drained.

The actuator 90 has a piston 93 that is movable by hydraulic pressure applied to the left and right chambers 91 and 92, and a rod 94 is connected to this piston 93, and the shift fork 32 of the dog clutch 8 is connected to the middle of the rod 94. ing. Further, a spring 95 is housed in the left chamber 92, and always urges the piston 93 to the left, that is, in the direction of non-direct connection. When the hydraulic pressure is introduced into the left chamber 91 during switching to direct drive, the rod 94 is urged to the right, but when the dog clutch 8 is in the head-butting state, the mouth rad 94 does not move to the right and the shift fork 32 also does not move to the right. Therefore, the spool 8 of the lock-up control valve 80
2 cannot move to the position where it hits the shift fork 32 and drains the port 86, so there is no risk that the clutch 20 will be disengaged.

In other words, the clutch 20
can maintain the connected state and prevent the engine from revving up.

The control circuit 100 includes an input rotation speed N table of the input shaft 6 and an output rotation speed N of the output shaft 31. is input as an electrical signal,
The first to third solenoid valves 101 to 101 depending on the running condition
103 is turned on and off. In addition,
The first solenoid pulp 1.01 is used not only for simple ON/OFF control, but also for so-called duty control that changes the ratio of ON time and OFF time within a constant cycle signal to generate an average oil pressure. You may go.

The operation of the above hydraulic control device is summarized as follows.

(2) The pulley ratio of the V-belt type continuously variable transmission section 10 shifts to the low speed ratio side when the first solenoid valve 101 is ON, and shifts to the high speed ratio side when the first solenoid valve 102 is OFF.

■The power intermittent clutch 20 is disconnected when the throttle opening is fully closed or close to fully closed and the second solenoid valve 102 is ON, or when the second solenoid valve 102 is turned on.
2 is OFF and the third solenoid valve 103 is ON.

(2) The dog clutch 8 is engaged (directly coupled drive) when the third solenoid valve 103 is ON, and is cut off (belt drive) when the third solenoid valve 103 is OFF.

In the transmission having the above configuration, the dog clutch 8, the direct coupling gear 7, the counter gear 28. The final reduction gear 29 and the differential device 30 form a direct drive path, while the external gear 9. Internal gear 12, ■ Belt continuously variable transmission section 10. Clutch 20, forward gear 21. Counter gear 2
8. Final reduction gear 29. The differential device 30 forms a belt drive path. The direct gear ratio i' between the input shaft 6 and the output shaft 31 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 31 in the belt drive path.

Figure 3 illustrates the above relationship, where A is the lowest speed line when belt drive, B is the highest speed line when belt drive, and C is the shift line when direct drive. C is located on the slightly lower speed side than the maximum speed line B during belt drive.

Generally, to switch from belt drive to direct drive, first accelerate along the lowest speed ratio line A of belt drive, and when the input rotation speed (or engine rotation speed) reaches a predetermined value, It is sufficient to shift to a high-speed ratio side while maintaining this rotational speed, and when the gear ratio of the belt drive matches the direct-coupling gear ratio, the dog clutch 8 is engaged to switch to the direct-coupling drive. However, the pulley ratio of the belt bottom continuously variable transmission section 10 is constantly changing, and even if you try to switch the dog clutch 8 at the moment when the belt drive gear ratio matches the direct gear ratio, the spline teeth of the dog clutch 8 You may get headbutted and be unable to shift. The present invention eliminates such shift defects and makes it possible to reliably switch to direct drive.

Here, an example of the direct connection control of the present invention by the control circuit 100 will be explained with reference to FIG.

First, when the operation starts, input the input rotation speed NI (1
10) and output rotation speed N. (111) and calculates the actual gear ratio i (-N+/No) during belt drive from the input rotation speed N and output rotation speed NO (112), and then directly connects it to the gear ratio i. The drive path is compared with the directly connected gal i' (113).

If the gear ratio i is larger than the direct-coupling gear ratio i' (on the low-speed ratio side), it means that the gear ratio i has not reached a state where it can be directly coupled, so the third solenoid valve 103 is set to 0FFL (
114), the actuator 90 is urged in the non-direct connection direction and returned.

If the gear ratio i is smaller than the direct coupling gear ratio i' (high speed ratio side), it means that a state where direct coupling is possible has been reached, so turn on the third solenoid valve 103 (115) and move the actuator 90 in the direct coupling direction. to energize. Then, the speed ratio i and direct gear ratio i again.

116), if the gear ratio i is larger than the direct gear ratio i'' (lower gear ratio side), the first solenoid valve 101
is set to 0FFL (117), and the oil pressure to the oil pressure chamber 18 is lowered to shift to the high speed ratio side. On the other hand, when the gear ratio i is smaller than the direct gear ratio i' (high speed ratio side), the first solenoid valve 101 is turned on (11B) to increase the oil pressure to the hydraulic chamber 18 and shift to the low speed ratio side.

After performing the above reciprocating control, the direct connection switch 35 is turned on.
If the direct coupling switch 35 is in the OFF state, it means that the switching of the dog clutch 8 to the direct coupling drive is not completed, so the above-mentioned reciprocating control is repeated. When the direct coupling switch 35 is turned on, it means that the switching to direct coupling drive is completed, so the first solenoid valve 101 is turned off (120) and the direct coupling control is completed.

''-, the belt drive gear ratio i is reciprocally controlled with the direct connection gear ratio i'' set as the target value while the tongue clutch 8 is biased in the direct connection direction, so the input side of the tongue clutch 8 is Sleeve 8a and output side spline teeth 7a
slide back and forth relative to each other, and the spline teeth that were in a head-butting state engage at a certain moment, allowing the tongue clutch 8 to be easily engaged. Since the boat 86 of the lock-up control valve 80 is drained at the same time as the dog clutch 8 is engaged, the clutch 20 is disconnected and power transmission between the driven pulley 15 and the output shaft 31 is cut off. After the engagement of the dog clutch 8 is detected by the direct connection switch 35, the first solenoid valve 101 is maintained in the OFF state, thereby ending the reciprocating control and
By lowering the oil pressure, only the V-belt heating stage transmission section 10 is shifted to the high speed ratio side, and is idled in a no-load state.

As a method for switching to direct drive, in addition to the present invention, it is also possible to perform reciprocating control for a certain period of time, for example, but since the time required for engagement of the donklilassochi 8 depends on the presence or absence of a head butt state, Even after a certain period of time has elapsed, it is unclear whether or not the dog clutch 8 has completely engaged. In the present invention, since the completion of engagement of the tongue clutch 8 is detected by the direct connection switch 35, there is no risk of ending the reciprocating control with incomplete engagement of the dog clutch 8, and reliable direct connection switching can be performed. can.

In the above embodiment, in order to detect the movement of the dog clutch 8 to the direct connection position, the position of the shift fork 32 is detected by the direct connection switch 35, but the position of the switching sleeve 8a or the rod 94 can be detected by the direct connection switch. May be detected.

Effects of the Invention As is clear from the above explanation, according to the present invention, by reciprocally controlling the gear ratio during belt drive using the direct gear ratio as the target value, the spline teeth of the dog clutch can be slid back and forth. This allows the dog clutch to engage quickly. In addition, since the engagement of the dog clutch is detected by the direct connection switch and this signal is used to terminate the reciprocating control, reliable direct connection control can be performed.

[Brief explanation of drawings]

FIG. 1 is a skeleton diagram of a first embodiment of the present invention, FIG. 2 is a circuit diagram of a hydraulic control device, FIG. 3 is a shift diagram, and FIG. 4 is a flowchart showing the operation of the control circuit. 6... Input shaft, 7... Direct connection gear, 8... Dog clutch, 10... ■ Belt type continuously variable transmission section, 20...
・Power intermittent clutch, 28... Counter gear (direct connection gear), 30... Differential device, 31...
・Output shaft, 32... Shift fork, 35... Direct connection switch, 40... Pulley control valve, 50... Kickdown control valve, 60... Throttle valve,
70...Clutch control valve, 80...Lockup control valve, 90...Actuator, 100...
- Control circuit, 101-103... solenoid valve.

Claims (1)

[Claims] (1) A direct drive path including a direct gear train and a belt drive path including a V-belt continuously variable transmission section are provided in parallel between the input shaft and the output shaft, and when the direct drive path is in the middle of the direct drive path, A transmission that is provided with a dog clutch that is engaged, and a power intermittent clutch that is engaged when the belt is driven in the middle of the belt drive path, and the gear ratio of the direct drive path is on the lower speed side than the maximum speed ratio of the belt drive path. When switching from belt drive to direct drive, the gear ratio of the belt drive path is controlled reciprocally using the direct drive gear ratio as the target value, and when the dog clutch operates to the direct drive position, this is detected by the direct drive switch, and the above A direct-coupling control method for a transmission characterized by terminating reciprocating control.