JP2651810B2 - Power transmission device with continuously variable transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission having a continuously variable transmission used in a power transmission system of a vehicle.

[0002]

2. Description of the Related Art A conventional power transmission device having a continuously variable transmission in which an endless V-belt is stretched over a driving pulley and a driven pulley whose groove width can be changed is disclosed in Japanese Patent Application Laid-Open No. H10-163,873. JP-A-61-206862). In this power transmission device, a friction clutch is provided only between the drive shaft connected to the prime mover and the input shaft of the continuously variable transmission,
The output shaft of the continuously variable transmission is directly connected integrally with the driven shaft.

[0003]

However, in the power transmission device described above, a friction clutch is interposed only on the drive shaft connected to the prime mover and the input shaft of the continuously variable transmission, and this friction clutch serves as a starting clutch. Therefore, when the friction clutch is switched from the disengaged state to the connected state and the power of the prime mover is transmitted to wheels and the like via the friction clutch and the continuously variable transmission, not only the output portion of the friction clutch but also the continuously variable Much of the power of the prime mover was consumed for the acceleration of the prime mover, and the rotation speed of the prime mover slowed down, making it difficult for the vehicle to start suddenly.

[0004]

SUMMARY OF THE INVENTION The present invention relates to an improvement in a power transmission device having a continuously variable transmission which overcomes the above-mentioned drawbacks. In a power transmission device having a continuously variable transmission, a drive clutch is provided between an output member of the internal combustion engine and an input member of the continuously variable transmission, and an output member of the continuously variable transmission and the power A driven clutch is interposed between the output member of the transmission device and the drive clutch,
The clutch is engaged or disengaged in accordance with a shift range, and the driven clutch is configured such that, when the drive clutch is engaged, clutch torque is controlled in accordance with an operating state. is there.

According to the present invention, the continuously variable transmission and the driven clutch are connected to the output member of the internal combustion engine when the drive clutch is disengaged in accordance with the shift range. The load on the internal combustion engine is greatly reduced, the internal combustion engine can be started easily, and the fuel efficiency of the internal combustion engine in an idling state is good.

In the present invention, when the drive clutch is engaged, a driven clutch whose clutch torque is controlled in accordance with the operating state is connected to the output member of the continuously variable transmission and the output member of the power transmission device. As a result, the output side rotational inertia load of the driven clutch is low, and as a result, the output member of the power transmission device on the output side of the driven clutch can rapidly accelerate, and Good acceleration in power transmission transient state and high power transmission efficiency.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention applied to a vehicle.

[0008]

First, the structure of a power transmission device 1 shown in FIGS. 1 and 2 will be described. The casing 2 of the power transmission device 1 includes an engine casing 10, a clutch casing 11, a transmission casing 12, and a side cover 13. The engine casing 10 is detachably mounted on a crankcase of an engine (not shown). The clutch casing 11 and the transmission casing 12 are detachably mounted with bolts 14, and the side cover 13 is detachably mounted on the transmission casing 12 with screws (not shown).

The drive shaft 15 is rotatably supported on the engine casing 10 via a ball bearing 17 and is rotatably supported on a drive pulley fixing face 30 of the continuously variable transmission 3 via a needle bearing 18. The drive pulley fixing face 30 is connected to the clutch casing 11 and the transmission casing 12 via a ball bearing 17.
The ball 22 is interposed in the shaft outer circumferential axial groove 30a of the drive pulley fixed face 30 and the shaft inner circumferential groove 31a of the drive pulley movable face 31, and the drive pulley fixed face is rotated. The drive pulley movable face 31 is reciprocally fitted in the axial direction without causing a relative rotational movement on the drive gear 30, and the drive gear 16 integrated with the drive shaft 15 is connected to a ring gear integrated with a crankshaft of an engine (not shown). When the engine is started, the drive shaft 15 is driven to rotate, and the drive pulley fixing face
When 30 rotates, the drive pulley movable face 31
Can rotate further together.

Further, the driven pulley fixing face 32 of the continuously variable transmission 3 is rotatably supported by the engine casing 10, the clutch casing 11, and the transmission casing 12 via the ball bearing 17, and is driven by the driven pulley fixing face 32. The movable face 33 is the drive pulley fixed face 30 and the drive pulley movable face 31
The driven shaft 19 is rotatably fitted to the driven pulley fixing face 32 via the needle bearing 18, and the output gear 20 and the parking gear 21 having a larger diameter are integrally formed on the driven shaft 19. The output gear 20 is meshed with a gear that is integral with a rear axle (not shown), and when the driven pulley fixed face 32 is in a rotating state, the driven pulley movable face 33 is also integrally rotated, and the driven shaft 19 is also rotated. When driven, the rear wheels can rotate.

A parking claw (not shown) is provided which can be removably engaged with the parking gear 21. When the parking claw is engaged with the parking gear 21, the parking gear 21 has a large diameter. Therefore, the load applied to the parking gear 21 is greatly reduced.

Further, a drive pulley movable face 31 is provided.
A drive pulley oil chamber 34 is attached to the drive pulley, and a driven pulley oil chamber 35 is attached to the driven pulley movable face 33. The drive pulley oil chamber 34, the driven pulley oil chamber
A drive pulley oil passage 36 and a driven pulley oil passage 37 communicating with the respective 35 are formed in the drive pulley fixed face 30 and the driven pulley movable face 33, and the drive pulley fixed face 30, the drive pulley movable face 31 and
A V-belt 38 is bridged between the driven pulley fixed face 32 and the driven pulley movable face 33.

The pressure of the pressure oil supplied to the driven pulley oil chamber 35 via the driven pulley oil passage 37 is lower than the pressure of the pressure oil supplied to the drive pulley oil chamber 34 via the drive pulley oil passage 36. When it is high, as shown in FIG. 1, the driven pulley movable face 33 approaches the driven pulley fixed face 32, the drive pulley movable face 31 is separated from the drive pulley fixed face 30, and the drive pulley fixed face 30, In the case where the winding radius of the drive pulley movable face 31 is larger than the winding radius of the driven pulley fixed face 32 and the driven pulley movable face 33 and the speed ratio of the continuously variable transmission 3 is large, As shown in FIG. 2, the speed ratio of the continuously variable transmission 3 is set to be small.

Further, a compression coil spring 23 is provided in each of the drive pulley oil chamber 34 and the driven pulley oil chamber 35, and the drive pulley movable face 31 and the driven pulley movable face 33 are formed by the spring force of the compression coil spring 23. Drive pulley fixed face 3
0, urged to approach the driven pulley fixed face 32.

A clutch outer 40 of the drive hydraulic clutch 4 is integrally spline-fitted to the drive shaft 15, and a clutch center 41 of the drive hydraulic clutch 4 is rotatably fitted to the drive shaft 15 via the needle bearing 18. A clutch piston 42 is slidably fitted to the clutch outer 40 to form a drive clutch oil chamber 43, and a drive clutch oil passage 44 communicating with the drive clutch oil chamber 43 is formed in the drive shaft 15, and the clutch On the right side of the piston 42, the clutch disc 45 engaging with the clutch outer 40 and the clutch plate 46 engaging with the clutch center 41 are overlapped with each other, and on the right side thereof, the pressure receiving plate 47 is engaged with the clutch outer 40, The disc spring 24 is interposed between the left clutch disc 45 and the clutch piston 42, and the clutch piston 42 A compression coil spring 23 that urges the clutch oil chamber 43 in a contracting direction is provided. When pressure oil is supplied to the drive clutch oil chamber 43 through the drive clutch oil passage 44, the compression coil spring 23 The clutch piston 42 is pushed rightward to overcome the force, the clutch disc 45 and the clutch plate 46 are pressed against each other, and the drive hydraulic clutch 4 is connected.

Further, a clutch outer 50 of the starting hydraulic clutch 5 is integrally fitted to the driven shaft 19, a clutch center 51 is spline-fitted to the driven pulley fixing face 32 of the continuously variable transmission 3, and a clutch piston is fitted to the clutch outer 50. 52 is slidably fitted to form a starting clutch oil chamber 53, and a starting clutch oil passage 54 communicating with the starting clutch oil chamber 53 is formed through the driven shaft 19 and the driven pulley fixing face 32. On the right side of the clutch piston 52, a clutch disk 55 engaging with the clutch outer 50 and a clutch plate 56 engaging with the clutch center 51 are overlapped with each other, and a pressure receiving plate 57 engages with the clutch outer 50 on the right side thereof. When pressure oil is supplied to the starting clutch oil chamber 53 through the starting clutch oil passage 54, the clutch piston 52 is pushed rightward. It is clutch disks 55 and clutch plates 56 are pressed against each other, shifting oil pressure clutch 5 is to be connected.

Thus, the reverse rotation mechanism 6 is arranged at the clutch center 41 of the drive hydraulic clutch 4 and the drive pulley fixing face 30 of the continuously variable transmission 3. That is, the reverse gear 60 is rotatably fitted to the input end member 39 spline-fitted to the drive pulley fixing face 30 via the needle bearing 18 at a position opposite to the clutch center 41. The shifter 61 that is spline-fitted to the member 39 is the clutch center 41 or the reverse gear.
60 can be selectively engaged.

An input gear 62 is formed integrally with the clutch center 41 of the drive hydraulic clutch 4. The input shaft 62 is directed parallel to the drive shaft 15, and a gear shaft 63 is mounted on a pump casing 72 of the gear pump 7 and a clutch casing 11. The gear shaft 63 is rotatably supported via a bearing 17, and the gear shaft 63 has a driven gear 64 that meshes with the input gear 62,
An intermediate gear 65 meshing with a reverse gear 60 via an idler gear (not shown) is formed integrally with the shifter.
When the shift fork 66 is engaged with 61 and the shift fork 66 is operated as shown by a solid line or a dotted line in the drawing, the rotational force of the clutch center 41 is directly applied to the drive pulley fixing face via the input end member 39. 30 to the input gear 62, driven gear 64, intermediate gear 65, idler gear, reverse gear 60 (not shown).
Then, the power is transmitted to the drive pulley fixing face 30 in the opposite direction via the input end member 39.

Further, one pump gear 70 of the gear pump 7 is spline-fitted to the drive shaft 15, and the pump gear 71 and the pump gear 70 meshing with the pump gear 70 are surrounded by the engine casing 10 and the pump casing 72, and the gear pump 7 is It is configured.

Further, a centrifugal governor 8 is provided on the gear shaft 63 of the reversing mechanism 6 between the driven gear 64 and the intermediate gear 65.
A governor piston 80 is slidably fitted to the gear shaft 63 in a direction perpendicular to the rotation axis of the 63 to form a valve chamber 82, and a governor weight 83 is attached to the governor piston 80 on the side opposite to the spool 81. The coil spring 26 is interposed between the gear shaft 63 and the governor weight 83, an oil inflow path 84 communicating with the valve chamber 82 is formed at the center of the shaft of the gear shaft 63, and the valve chamber 82 is shifted toward the spool 81. An oil outflow passage 85 is formed to communicate with the oil inflow passage 84, and the oil inflow passage 84 is connected to a discharge portion 73 of the pump gear 70 via an inflow pipe 86. The pressure of the pressurized oil discharged to the oil outflow passage 85 gradually increases as the rotation speed of the gear shaft 63 increases.

Next, the hydraulic circuit 100 of the power transmission device 1 shown in FIGS. 3 to 7 will be described. Hydraulic pressure setting unit 10
1 is provided with a relief valve 103 which communicates with the discharge portion 73 of the gear pump 7.
A sub-valve 104 is slidably fitted further downstream, and a piston valve 106 is further slidably fitted to the sub-valve 104. A ratio-linked regulator spring 107 is interposed between the piston valve 106 and the upper part of the main body 102. A lever 108 integrally mounted on the sub-valve 104 projects outward from the main body 102 and is engaged with a ring 31a integral with the drive pulley movable face 31 of the continuously variable transmission 3 and is shown in FIG. When the drive pulley movable face 31 is separated to the right from the drive pulley fixed face 30 as shown in FIG.
At the top.

Then, the hydraulic pressure at the discharge portion 73 of the gear pump 7 rises, and the piston valve 106 is pushed upward by the low-pressure hydraulic pressure that has entered the main body 102 from the relief valve 103, overcoming the spring force of the ratio-linked regulator spring 107. The piston valve 106 is raised from the position shown in FIG. 3 to the position shown in FIG.
Pressure oil flows into the inside.

A drive clutch hydraulic relief valve 109 and an oil supply relief valve 110 are provided in series downstream of the port 105 of the sub-valve 104, and the pressure oil of the oil supply passage 132 discharged from the port 105 of the sub-valve 104 is set. When the pressure exceeds the pressure, the drive clutch hydraulic relief valve 109 is opened and flows into the belt oil supply passage 142, and the oil pressure in the belt oil supply passage 142 reaches a value equal to or higher than the set pressure of the oil relief valve 110. Then, the oil supply relief valve 110 is opened and discharged to the oil tank 143.

Further, a start clutch oil pressure conversion valve 111 is attached to the main body 102 of the oil pressure setting unit 101. The start clutch oil pressure conversion valve 111 has a large diameter valve body 111a, a small diameter valve body 111b, and both of them. Spring receiver 111c interposed in 111b, large-diameter coil spring 111d interposed in large-diameter valve main body 111a and spring receiver 111c, and small-diameter coil spring interposed in small-diameter valve main body 111b and setting section main body 102 A small hole 111f is provided in the lower side surface of the small-diameter valve body 111b, and the spring setting force Xd of the large-diameter coil spring 111d is set to be larger than the setting force Xe of the small-diameter coil spring 111e.

The starting clutch hydraulic pressure conversion valve 111 is provided with a tank return oil passage 112. The hydraulic pressure P _G of the centrifugal governor 8 increases quadratically as the engine speed Ne increases, as shown by the solid line in FIG. 13, but the large-diameter coil spring 111d and the small-diameter coil spring 111e increase. Since there is a difference between the spring setting forces Xd and Xe and the former is larger, the small-diameter valve body 111b is pushed upward away from the large-diameter valve body 111a together with the spring receiver 111c, and the small hole 111f is The low-pressure oil flows into the small-diameter valve body 111b through the low-pressure oil passage 131, and the downward pressing force P _C · S of the small-diameter valve body 111b due to the low-pressure oil.
_B and (although the pressure receiving area of S _B small diameter valve body 111b),
Such that the sum of the spring setting force Xe of the small-diameter coil spring 111e is equal to the spring set force Xf of the large-diameter coil spring 111d, the creep pressure P _C in the starting clutch oil passage 139 is maintained. When this is displayed using a formula,

[0026]

[Number 1] _{P C · S B + Xe =} Xd

That is, the creep oil pressure P _c is

(Equation 2)

Further centrifugal governor oil pressure P _G is increased, the large-diameter valve upper upward force P _G · S _A (pressure receiving area of the proviso S _A large-diameter valve body 111a) acting on the main body 111a large-diameter coil spring 111d Is greater than the spring setting force Xd of

[Equation 3] P _G・ S _A > Xd

[0029] The centrifugal governor hydraulic pressure P _G is,

(Equation 4) , The hydraulic pressure P _S in the starting clutch oil passage 139 increases quadratically and changes as shown by the broken line in FIG.
The starting hydraulic clutch 5 shifts to the connected state.

Further, the body 102 has a ratio switching valve.
113 is provided, and two lands 115 of the spool 114 are provided.
, 116 are connected to a high-pressure oil passage 130 through a high-pressure oil inflow port 119, and a central ring-shaped recess 118 between the lands 115, 116 is connected through a low-pressure oil inflow port 120. The low-pressure oil passage 131 communicates with the drive pulley oil supply port 121 via the drive pulley oil passage 136 and the drive pulley oil chamber 34, and the driven pulley oil supply port 122 communicates with the driven pulley oil passage 137 via the driven pulley oil passage 137. It is connected to room 35.

As shown in FIG. 8, the ratio switching valve 113 is constructed in an exaggerated manner. That is, the distance between the lands 115 and 116 is greater than the distance between the drive pulley lubrication port 121 and the driven pulley lubrication port 122.
When the spool 114 is located at the center, a ring-shaped recess 117 at both ends is provided with a drive pulley lubrication port.
121 and the driven pulley lubrication port 122 are closed, and the central ring-shaped recess 118 is both closed by the drive pulley lubrication port 121 and the driven pulley lubrication port 122, and the low-pressure oil in the low-pressure oil passage 131 is driven. The oil is supplied to the pulley oil chamber 34 and the driven pulley oil chamber 35 (see FIG. 10), and the tension of the V-belt 38 is controlled by the low-pressure oil.

A cylindrical spring receiver 123 is slidably fitted on the main body 102 at a position above the axis of the spool 114, and a compression coil spring 124 is interposed on the spool 114 and the spring receiver 123. This compression coil spring
A lever 125 is pivotally mounted to apply a compressive force to the throttle 124. The lever 125 is connected to a throttle grip (not shown), and is operated when an engine throttle valve (not shown) is opened. Is
The lever 125 rotates counterclockwise, and the spring receiver 123,
The spool 114 is pushed downward via a compression coil spring 124.

The manual valve 127 can take five positions: neutral N, drive D, forward F, reverse R, and parking P. In the neutral N setting state, as shown in FIG. The oil passage 133 is connected to an engine speed detecting oil passage 140 which communicates with the engine speed corresponding oil chamber 126 of the ratio switching valve 113.

In the drive D setting state, as shown in FIG. 5, the centrifugal governor oil passage 133 is connected to the engine speed detection oil passage 140, and the oil supply passage 132 is connected to the forward oil passage 134. The forward oil passage 134 is connected to the drive hydraulic clutch 4 via a forward / reverse switching servo valve 128 and a drive clutch oil passage 138.

Further, in the forward F setting state, as shown in FIG. 6, the connection state is set in the same manner as the drive D setting state, and the centrifugal governor oil passage 13 is provided outside the connection state.
3 is connected to the starting clutch oil pressure conversion oil passage 141, and the starting clutch oil pressure conversion oil passage 141 is connected to the oil pressure conversion port 111g of the starting clutch oil pressure conversion valve 111.
The high-pressure oil is supplied to the starting hydraulic clutch 5 when the engine speed becomes higher than the drive D setting state.

In the reverse R setting state, FIG.
As shown in FIG. 2, the supply passage 132 is connected to a retreat oil passage 135, and the low-pressure oil is supplied from the refuel passage 132 to the retreat oil passage 135 and a reverse inhibitor valve 129 interposed in the retreat oil passage 135.
Through a drive clutch oil passage 138, and is supplied to the drive hydraulic clutch 4 via a drive clutch oil passage 138.
128 is switched to the reverse side, the shift fork 66 is shifted to the reverse side, the reverse rotation mechanism 6 is switched, and the continuously variable transmission 3 is reversely rotated. At this time, the engine speed detecting oil passage 140 communicating with the engine speed corresponding oil chamber 126 of the ratio switching valve 113 is connected to the oil tank 143, and the ratio switching valve 113 remains set at a low speed (ratio hold).

Further, in the parking P setting state, the centrifugal governor oil passage 133 is closed in the manual valve 127, and the communication with the engine speed detection oil passage 140 and the starting clutch oil pressure conversion oil passage 141 is cut off. 13
2 is connected to the oil tank 143 in the manual valve 127, and when the reverse R is set, the forward / backward switching servo valve is
The low-pressure oil existing in 128 is discharged to an oil tank 143 through a retreat passage 135 and a reverse inhibitor valve 129.

[0038]

Since the illustrated embodiment is constructed as described above, when the engine is stopped and the manual valve 127 is set to neutral N, the gear pump 7 is stopped to generate hydraulic pressure. The drive pulley movable face 31 and the driven pulley movable face are formed by the spring force of the compression coil spring 23 attached to the drive pulley movable face 31 of the continuously variable transmission 3 and the compression coil spring 23 attached to the driven pulley movable face 33. 33 is pressed against the drive pulley fixing face 30 and the driven pulley fixing face 32, respectively, and the V-belt 38 can maintain a tensioned state.

When the engine is started with the manual valve 127 set to neutral N, the gear pump 7 is driven to rotate, and a hydraulic pressure is generated in the hydraulic circuit 100 as shown in FIG.

A part of the pump pressure oil discharged from the gear pump 7 is sent to the oil inflow path 84 of the centrifugal governor 8, but a part of the pump pressure oil discharged from the gear pump 7 is supplied to the oil inflow path 84 of the centrifugal governor 8. When the manual valve 127 is set to the neutral position N as shown in FIG. 4, the oil supply passage 132 is not communicated with the forward oil passage 134, so that the pressure oil in the oil supply passage 132 Is manual valve 127, forward oil passage 134, forward / backward switching servo valve
The drive hydraulic clutch 4 is not supplied to the drive hydraulic clutch 4 via the drive clutch oil passage 128 and the drive clutch oil passage 138, so that the centrifugal governor 8
Does not rotate, the pressure oil in the oil inflow passage 84 cannot flow into the inflow pipe 86, and no pressure oil is supplied below the large-diameter valve body 111a of the start clutch hydraulic pressure conversion valve 111, and the start clutch The small hole 111f of the hydraulic pressure conversion valve 111 is
No hydraulic fluid is supplied to the starting hydraulic clutch 5 through the starting clutch oil passage 139, and the starting hydraulic clutch 5 is not engaged.

In the neutral N state, even if the centrifugal governor oil passage 133 and the engine speed detecting oil passage 140 are in communication, the centrifugal governor 8 stops and the oil inflow passage 84
The pressure oil is not supplied to the engine speed corresponding oil chamber 126 through the centrifugal governor oil passage 133 and the engine speed detection oil passage 140 because the oil pressure is not supplied to the oil chamber 126 corresponding to the engine speed. As a result, the pump pressure oil higher than the oil pressure in the low-pressure oil passage 131 is supplied to the driven pulley oil chamber 35 through the driven pulley oil passage 137, and the spool 114 is positioned below. The pressure oil in the low-pressure oil passage 131 is supplied to the drive pulley oil passage 136.
Is supplied to the drive pulley oil chamber 34 via the

From such a neutral N setting state,
When the manual valve 127 is switched to the drive D setting state, as shown in FIG.
At 127, the oil supply passage 132 is communicated with the forward oil passage 134, so that the low-pressure oil discharged from the piston valve 106 to the oil supply passage 132 via the port 105 passes through the forward oil passage 134 and the forward / backward switching operation interposed therebetween. The drive shaft 15, which is supplied to the drive hydraulic clutch 4 via the servo valve 128 and is rotationally driven by the engine, is connected to the drive pulley fixed face 30, and the continuously variable transmission 3 is in a rotationally driven state.
At this time, since the hydraulic pressure in the driven pulley oil chamber 35 is higher than the hydraulic pressure in the drive pulley oil chamber 34, the driven pulley movable face 33 approaches the driven pulley fixed face 32 as shown in FIG. The driven pulley fixed face 3 is larger than the winding radius of the V belt 38 on the drive pulley fixed face 30 and the drive pulley movable face 31.
2. V-belt 38 on driven pulley movable face 33
Becomes larger, the transmission ratio N ₁ / N ₂ (N ₁ : input shaft rotation speed, N ₂ : output shaft rotation speed) of the continuously variable transmission 3 increases, and the drive pulley movable face 31 Of 31a
The lever 108 engaged with the lever 108 moves upward in FIG. As the lever 105 rises, the port 105 of the sub-valve 104 also rises, so that the ratio-linked regulator spring 107 is strongly compressed, the spring force of the ratio-linked regulator spring 107 increases, and in order to open the port 105, the piston valve 106 is opened. The upward force corresponding to the product of the difference between the upper and lower cross-sectional areas and the oil pressure in the sub-valve 104 increases, and as a result, as shown in FIG. The pressure P ₂ is set to P _20, and the pressure P ₁ of the high-pressure oil in the high-pressure oil passage 130 is set to P by the pressure difference setting by the relief valve 103.
₁₀ = is set to P ₂₀ + △ P.

When the engine speed increases and the centrifugal governor oil pressure rises, the starting clutch oil pressure conversion valve 11
1 is pushed upward to be opened, and the low-pressure oil in the sub-valve 104 is supplied to the starting hydraulic clutch 5 through the starting clutch oil passage 139 to be in the clutch-in state, and the vehicle is gradually accelerated at the maximum gear ratio. (X ₁ line in FIG. 11)

[0044] Also when the shifting oil pressure clutch 5 becomes completely connected state (A ₁ point), the engine speed corresponding oil chambers ratio switching valve 113 is accompanied to the increase of the centrifugal governor hydraulic
The pressure in 126 also rises, and the spool 114 rises by overcoming the spring force of the compression coil spring 124. When the spool 114 is located at the center of the stroke, the central ring-shaped recess 11 is formed.
8 communicates not only with the driven pulley lubrication port 122 but also with the drive pulley lubrication port 121, and as shown in FIG. 10, the low-pressure oil in the low-pressure oil passage 131 is supplied to the drive pulley oil chamber.
34 and the driven pulley oil chamber 35. In addition, the engine speed has increased and the engine speed
When the pressure in 126 increases, the spool 114 rises, and the supply state of the pressurized oil to the drive pulley oil chamber 34 and the driven pulley oil chamber 35 is reversed. low pressure oil is introduced, the gear ratio is reduced (Y ₁ line in FIG. 11)

[0045] In this case, the clutch stall torque (torque balanced and the engine torque and the clutch torque) of the starter hydraulic clutch 5 in A ₁ point of FIG. 11 what was akgm as illustrated in FIG. 12, since the required torque in conjunction with a change of the transmission ratio of the vehicle becomes bkgm decreased, stall curve Y ₁ of the power transmission device 1 becomes downhill in FIG.

However, when the power transmission device is configured to engage the drive hydraulic clutch 4 in accordance with the engine speed, the stall curve becomes y in FIG.
_As shown by the line _1, it is straight in the lateral direction, and the stall region in the high vehicle speed range is wide and the power transmission efficiency is low.However, in this embodiment, the stall speed of the engine is reduced with the change in the shift ratio. Power transmission efficiency is high due to the reduced stall area.

When the throttle is operated to open the throttle valve to increase the engine output and rotate the lever 125 counterclockwise, the spool 114 is pushed down via the compression coil spring 124, Since the ratio switching valve 113 operates so as to increase the gear ratio, the acceleration of the vehicle is high.

From the drive D setting state, the forward F
When switching to the setting state, in the drive D setting state,
Hydraulic pressure conversion port 111a of start clutch hydraulic pressure conversion valve 111
The start clutch oil pressure conversion oil passage 141 that opens to the side cover 13 communicates with the side cover 13, the area where the governor oil pressure acts on the start clutch oil pressure conversion valve 111 is reduced, and the start clutch oil pressure conversion is performed unless the engine rotates at a higher rotation speed. valve 111 is prevented from being opened (see a ₂ in FIG. 11).

For this reason, the starting hydraulic clutch 5 is engaged and disengaged in a region where the engine speed is high, so that rapid acceleration becomes possible.

Next, when the state is switched from the neutral N setting state to the reverse R setting state, the engine speed detecting oil passage 140 connected to the centrifugal governor oil passage 133 is shut off. The continuously variable transmission 3 is set to the maximum speed ratio irrespective of the change in the engine speed, and the refueling passage 132 is connected to the reversing oil passage 135 so that the pressure oil Is supplied to the forward / backward switching servo valve 128, the forward / backward switching servo valve 128 is switched, and the switching operation switches the reverse rotation mechanism 6 to reverse, so that the vehicle can be moved backward.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view illustrating an embodiment of a power transmission device including a continuously variable transmission according to the present invention, and is a diagram illustrating a state where a gear ratio is large.

FIG. 2 is a longitudinal sectional view similar to FIG. 1 illustrating an embodiment of a power transmission device having a continuously variable transmission according to the present invention, and showing a state in which a gear ratio is small.

FIG. 3 is a hydraulic circuit diagram in a state where a manual valve is set to neutral N.

FIG. 4 is a hydraulic circuit diagram illustrating a flow state of pressure oil in a state where a manual valve is set to neutral N.

FIG. 5 is a hydraulic circuit diagram illustrating a flow state of pressure oil in a state where a manual valve is set to overdrive D.

FIG. 6 is a hydraulic circuit diagram illustrating a flow state of pressure oil when a manual valve is set to forward F.

FIG. 7 is a hydraulic circuit diagram illustrating a flow state of pressure oil in a state where a manual valve is set to reverse R.

FIG. 8 is an enlarged longitudinal sectional view of a main part of the ratio switching valve.

FIG. 9 is a characteristic diagram showing how the low pressure oil and the respective oil pressures of the high pressure oil having a constant differential pressure change in accordance with the gear ratio in the oil pressure setting unit.

FIG. 10 is a diagram illustrating a state in which pressure oil is supplied to a drive pulley oil chamber and a driven pulley oil chamber in accordance with a stroke of a ratio switching valve.

FIG. 11 is a power transmission characteristic diagram illustrating a relationship between a vehicle speed and an engine speed in the embodiment of the present invention.

FIG. 12 is a drawing illustrating the relationship between the engine speed, the speed of the drive hydraulic clutch, and the torque required for traveling.

FIG. 13 is a characteristic diagram illustrating governor oil pressure characteristics and start clutch oil pressure characteristics.

FIG. 14 is a characteristic diagram of a conventional power transmission device.

[Brief description of reference numerals]

DESCRIPTION OF SYMBOLS 1 ... Power transmission device, 2 ... Casing, 3 ... Continuously variable transmission,
4: Drive hydraulic clutch, 5: Start hydraulic clutch, 6
… Reversing mechanism, 7… Gear pump, 8-point centrifugal governor, 10…
Engine casing, 11… Clutch casing, 12… Mission casing, 13… Side cover, 14… Bolt,
15 ... drive shaft, 16 ... drive gear, 17 ... ball bore, 18
… Needle bearing, 19… driven shaft, 20… output gear, 21
... parking gear, 22 ... ball, 23 ... compression coil spring, 24 ... disc spring, 25 ... seal ring, 26 ... coil spring, 30 ... drive pulley fixed face, 31 ... drive pulley movable face, 32 ... driven pulley fixed face, 33: driven pulley movable face, 34: drive pulley oil chamber, 35: driven pulley oil chamber, 36: drive pulley oil passage, 37: driven pulley oil passage, 38: V belt,
39 ... input end member, 40 ... clutch outer, 41 ... clutch center, 42 ... clutch piston, 43 ... drive clutch oil chamber, 44 ... drive clutch oil passage, 45 ... clutch disc, 46 ... clutch plate, 47 ... pressure receiving plate, 50: clutch outer, 51: clutch center, 52: clutch piston, 53: starting clutch oil chamber, 54: starting clutch oil passage, 55: clutch disc, 56: clutch plate, 57
... pressure receiving plate, 60 ... reverse gear, 61 ... shifter, 62 ... input gear, 63 ... gear shaft, 64 ... driven gear, 65 ... intermediate gear, 66 ... shift fork, 70, 71 ... pump gear, 72 ...
Pump casing, 73 ... Discharge part, 80 ... Governor piston, 81 ... Spool, 82 ... Valve, 83 ... Governor weight,
84 ... oil inflow path, 85 ... oil outflow path, 86 ... inflow pipe, 87 ... outflow pipe, 100 ... hydraulic circuit, 101 ... hydraulic setting section, 102 ...
Main body, 103… Relief valve, 104… Sub valve, 105
… Port, 106… Piston valve, 107… Ratio-linked regulator spring, 108… Lever, 109… Drive clutch hydraulic relief valve, 110… Oil relieving valve, 111… Start clutch hydraulic pressure conversion valve, 112… Tank return oil passage, 113… Ray switching valve, 114 ... Spool, 115, 116 ... Land, 117 ... Ring-shaped recess at both ends, 11
8… Central ring-shaped recess, 119… High-pressure oil inflow port, 120
… Low-pressure oil inlet port, 121… Drive pulley oil supply port, 122… Driven pulley oil supply port, 123… Spring receiver, 124… Compression coil spring, 125… Lever, 126
… Oil chamber for engine speed, 127… manual valve, 128… forward / backward switching servo valve, 129… reverse inhibitor valve, 130… high pressure oil passage, 131… low pressure oil passage, 132… oil supply passage, 133… centrifugal governor oil passage ,13
4 ... forward oil passage, 135 ... retreat oil passage, 136 ... drive pulley oil passage, 137 ... driven pulley oil passage, 138 ... drive clutch oil passage, 139 ... starting clutch oil passage, 140
... oil passage for detecting engine speed, 141 ... oil passage for starting clutch oil pressure conversion, 142 ... oil supply passage for belts, 143 ... oil tank.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location F16H 63:06 (72) Inventor Yoshitaka Sekiguchi 1-4-1 Chuo, Wako-shi, Saitama Honda Co., Ltd. Inside the Technical Research Institute (56) References JP-A-63-110045 (JP, A) JP-A-63-57959 (JP, A) JP-A-63-188537 (JP, A)

Claims (1)

(57) [Claims] 1. A power transmission device in which a continuously variable transmission is interposed between an output member of an internal combustion engine and an output member of a power transmission device, wherein the output member of the internal combustion engine and the input member of the continuously variable transmission are connected to each other. A drive clutch is interposed, and a driven clutch is interposed between the output member of the continuously variable transmission and the output member of the power transmission device. A power transmission device having a continuously variable transmission, wherein the driven clutch is configured to control a clutch torque in accordance with an operation state when the drive clutch is engaged.