JPS61167763A - Hydraulic device for transmission for vehicle - Google Patents

Abstract

PURPOSE:To prevent the occurrence of the slip of a belt, by a method wherein the hydraulic pump of a transmission is coupled to the engine of a vehicle through a first one-way clutch, and is coupled to a member to be driven in a power transmission route, running from a main clutch to driving wheels, through a second one-way clutch. CONSTITUTION:An engine 10 is coupled to a belt type transmission 16 through a main clutch 14, and a driving shaft 48 of a hydraulic pump 40 is operatively coupled to the engine 10 of a vehicle through a first one-way clutch 54. The driving shaft is operatively coupled to a rotary shaft 18 on the primary side, being a member to be driven, of a power transmission route, running from the main clutch 14 to driving wheels, through a second one-way clutch 56. This causes a hydraulic pump to be driven by the second one-way clutch even during release of the main clutch from engagement, maintains power transmission capability, and prevents the occurrence of the slip of a belt.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a hydraulic system for a vehicle transmission, and more particularly to a technique for driving a hydraulic pump for generating the hydraulic pressure necessary for operating the transmission.

BACKGROUND OF THE INVENTION Vehicles equipped with a transmission that changes the rotation of an engine and transmits the same to drive wheels are provided with a hydraulic system that includes a hydraulic pump for generating the hydraulic pressure necessary for operating the transmission. The hydraulic pump of such a hydraulic system is usually directly driven by an engine. For example, Utility Model Application No. 57-4353, Utility Model Application No. 58-1
Hydraulic systems described in Japanese Patent Application Laid-open No. 12761, Japanese Patent Application Laid-Open No. 58-225254, etc. are examples of this type of hydraulic system.

Problems to be Solved by the Invention However, in such conventional hydraulic systems, the hydraulic pump is directly driven by the engine. When the engine is stopped, the hydraulic pump also stops operating, making it difficult to control the transmission, which is operated by hydraulic pressure. Particularly, when the transmission is a belt-type continuously variable transmission whose power transmission capability is maintained by hydraulic pressure, belt slippage occurs.

On the other hand, it is conceivable to provide a first hydraulic pump that is directly driven by the engine and a second hydraulic pump that is driven by a driven member, but in such a hydraulic system, the device It had the disadvantage that it was too large to be used in vehicles.

Means for Solving the Problems The present invention has been made against the background of the above circumstances.
The gist of this is that in vehicles where an engine and a transmission that changes the speed of the engine and transmits it to the drive wheels are connected via a main clutch, the hydraulic pressure required to operate the transmission is generated. A hydraulic system including a hydraulic pump, wherein the hydraulic pump is operatively connected to the engine of the vehicle via a first one-way clutch, and the hydraulic pump is operatively connected to the engine of the vehicle via a second one-way clutch, and the hydraulic pump is connected to the drive from the main clutch via a second one-way clutch. It is operatively connected to the driven member of the power transmission path leading to the wheel.

Operation and Effects of the Invention With this arrangement, when the engine is normally operating, the hydraulic pump is driven by the engine via the first one-way clutch, but if the main clutch is disengaged or Even when the output of the engine is not transmitted to a driven member downstream of the main clutch, the hydraulic pump is transmitted via the second one-way clutch by the driven member that rotates as the vehicle coasts. Driven. Therefore, the difficulty in controlling a vehicle transmission operated by hydraulic pressure is eliminated, and especially when the transmission is a belt-type continuously variable transmission whose power transmission ability is maintained by hydraulic pressure. This will prevent the belt from slipping.

EXAMPLE Hereinafter, an example of the present invention will be described in detail based on the drawings.

In FIG. 1, a crankshaft 12 of a vehicle engine 10 is shown.
is connected to a primary rotating wheel 18 of a belt-type continuously variable transmission machine 16 via a main clutch 14.

The main clutch 14 is composed of a friction clutch, an electromagnetic clutch, a centrifugal clutch, a fluid clutch, or the like. A fixed rotating body 20 is fixed to the primary rotating shaft 18, and a movable rotating body 22 is provided so as to be non-rotatable around the axis but movable in the axial direction. 22 determines the V-groove width, in other words, the effective diameter (
Primary side variable pulley 1J that can change the hanging diameter of the transmission belt
24 are configured. A fixed rotating body 28 and a movable rotating body 30 are also provided on the secondary rotating shaft 26 of the belt-type continuously variable transmission 16. It is configured. Movable rotating body 22 of primary side variable boob IJ24
is adapted to be driven by the primary side hydraulic cylinder 34, and the movable rotating body 30 of the secondary side variable pulley 32 is driven by the primary side hydraulic cylinder 34.
is adapted to be driven by a secondary hydraulic cylinder 36. Here, the primary hydraulic cylinder 34 and the secondary hydraulic cylinder 36 have approximately the same pressure receiving area, and the diameters of the variable pulleys 24 and 32 are also approximately the same. A transmission belt 38 consisting of an endless annular hoop and a large number of blocks stacked on top of each other along the hoop is wound around the primary variable pulley 24 and the secondary variable pulley 32. The rotational force transmitted to the side rotating wheel 18 is transmitted to the secondary rotating shaft 26 via the transmission belt 38, and further transmitted to the drive wheels of the vehicle via an auxiliary transmission and a final reduction gear (not shown). It has become.

A constant displacement hydraulic pump 40 serving as a hydraulic pressure source sucks hydraulic oil in an oil tank (not shown) and pumps the hydraulic oil to a hydraulic control circuit 44 via a line oil passage 42 . In this hydraulic control circuit 44, for example, a belt-type stepless control circuit is provided that controls the flow rate of hydraulic oil supplied to the primary hydraulic cylinder 34 or the flow rate of hydraulic oil discharged from the primary hydraulic cylinder 34 to the drain. An electromagnetic flow control servo valve that changes the speed ratio of the transmission 16 and a flow rate of the hydraulic oil flowing out from the line oil passage 42 to the drain are used to control the line hydraulic pressure in the line oil passage 42 by the slippage of the transmission belt 38. A pressure regulating valve or the like is provided to change the pressure to a size that does not occur.

The hydraulic pump 40 is rotationally driven by the engine 10 in normal times, and when the vehicle is coasting, such as when the engine 10 is stopped during driving to improve fuel efficiency, the engine 10 is rotated. lO
When the output of the main clutch 14 is not transmitted to a driven member at a stage subsequent to the main clutch 14, it is rotationally driven by that driven member. That is, on the output side of the main clutch 14, a sleeve 46 that rotates together with the crankshaft 12 is provided on the outer periphery of the primary rotating ring 18, and a hydraulic pump is provided on the outer periphery of the sleeve 46 and the primary rotating ring 18. A gear 52 that meshes with a gear 50 fixed to a drive shaft 48 of 40 is rotatably provided, and between the sleeve 46 and the boss portion 53 of the gear 52,
A first one-way clutch 54 and a second one-way clutch 56 whose power transmission direction is the same as the rotational direction of the crankshaft 12 are interposed between the primary rotating wheel 18 and the boss portion 53 of the gear 52. It is being Therefore, when the main clutch 14 connects the crankshaft 12 and the primary rotating wheel 18 and the engine 10 drives the vehicle, the crankshaft 12. Sleeve 46, first one-way clutch 54. gear 5
0. The hydraulic pump 40 is driven by the engine lO via the drive shaft 48, but when the vehicle is not driven by the engine 10, such as when the engine 10 is stopped while the vehicle is running, the first one-way clutch 5
4 idles, the second one-way clutch 56. gear 50
．． The hydraulic pump 40 is driven by the primary rotating wheel 18, which rotates as the vehicle coasts, via the drive shaft 48.

As described above, according to this embodiment, the hydraulic pump 40 functions as a driven member when the vehicle is coasting and the output of the engine 10 is not transmitted to the driven member at the downstream stage than the main clutch 14. Since it is rotationally driven by the primary rotating shaft 18, even in such a case, it is possible to prevent the belt-type continuously variable transmission 16 from becoming difficult to control and to prevent the transmission belt 38 from slipping.

Next, another embodiment of the present invention will be described. In the following description, parts common to those in the above-described embodiments are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 2, the main clutch 58 has its drive side rotating body 6
0 and a driven rotating body 62 are hydraulically engaged and controlled by hydraulic pressure, and a drive shaft 48 of a hydraulic pump 40 is vertically connected to a primary rotating wheel 18 connected to the driven rotating body 62. The hydraulic pump 40 is disposed on the opposite side of the engine 10 with the primary variable pulley 24 interposed therebetween. The drive shaft 48 is connected to a drive side rotating body 60 via a first one-way clutch 54 on the engine 10 side, and is connected to the primary side rotating shaft 18 and a second one-way clutch 56 on the hydraulic pump 40 side. connected via. Since the power transmission direction of the first one-way clutch 54 and the second one-way clutch 56 is the same as the rotational direction of the crankshaft 12 as described above, this embodiment also has the same effect as the above-mentioned embodiment. In addition, there is an advantage that the gears 50 and 52 as in the above-mentioned embodiments are not required. Furthermore, according to the present embodiment, even if the engine 10 is stopped while the vehicle is running, the main clutch 58 can be controlled. For example, by re-engaging the main clutch 58 while the vehicle is running, There is an advantage that the engine 10 can be restarted.

Although the embodiment of the present invention has been described above based on the drawings, the present invention can also be applied to other aspects.

For example, in the embodiment described above, the primary rotating shaft 18
The hydraulic pump 40 is driven via the second one-way clutch 56, but the hydraulic pump 40 is driven by the secondary rotating shaft 26 or a driven member in the power transmission path at a later stage. It is okay to do so.

In addition, in the above-mentioned embodiment, the belt type continuously variable transmission 1
6 has been described, however, other types of vehicle transmissions such as automatic transmissions in which a plurality of gear stages are automatically switched under hydraulic control may be used.

In addition, in the embodiment shown in FIG. 1 described above, the gear 52.5
For example, if the hydraulic pump 40 is an internal gear pump, the boss of the driving gear itself is connected to the boss portion 5 of the gear 52.
3 may be configured. Even in this case, there is an advantage that the gears 52 and 50 are omitted.

Note that the above-mentioned embodiment is merely one embodiment of the present invention, and various modifications may be made to the present invention without departing from the spirit thereof.

[Brief explanation of the drawing]

FIG. 1 is a hydraulic circuit diagram showing one embodiment of the present invention. FIG. 2 is a diagram corresponding to FIG. 1 showing another embodiment of the present invention. 10: Engine 14.58: Main clutch 16:
Belt type continuously variable transmission (vehicle transmission) 18 Primary side rotating shaft (driven member) 40: Hydraulic pump 54: First one-way clutch 52: Second one-way clutch

Claims (2)

[Claims] (1) In a vehicle in which an engine and a transmission that changes the speed of the engine and transmits the rotation to the drive wheels are connected via a main clutch, a hydraulic pump is installed to generate the hydraulic pressure necessary for operating the transmission. A hydraulic system comprising: operatively connecting the hydraulic pump to the engine of the vehicle via a first one-way clutch, and transmitting power from the main clutch to the driving wheels via a second one-way clutch. A hydraulic system for a vehicle transmission, characterized in that it is operatively connected to a driven member of a transmission path. (2) The transmission includes a primary rotating shaft connected to the engine via the main clutch, a secondary rotating shaft, and a transmission belt provided on the primary rotating shaft and the secondary rotating shaft. is wound around a pair of variable pulleys, the hydraulic pump is connected to the engine via the first one-way clutch, and is connected to the primary side rotation via the second one-way clutch. A hydraulic system for a vehicle transmission according to claim 1, which is connected to a shaft.