JPH0589972U - Hydraulic power transmission coupling - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] With regard to hydraulic power transmission joints used to distribute the driving force of a vehicle, prevent pulsation of torque characteristics, and
The purpose is to prevent the occurrence of tight corner braking phenomenon. A band brake 26 is provided on the outer circumference of a rotor 5 connected to one of the input / output shafts, and a pin and a pin for pressing an end portion of the band brake 26 are urged to a housing 4 connected to the other input / output shaft. It is configured to provide a spring to operate.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a hydraulic power transmission joint used for distributing a driving force of a vehicle.

[0002]

[Prior Art]

 The applicant has proposed the following hydraulic power transmission joint in Japanese Patent Application No. 2-184735. That is, this hydraulic power transmission joint is provided between the input / output shafts that can rotate relative to each other, is connected to the one shaft, and has a cam housing on the inner side surface of which a cam surface having two or more peaks is formed; A rotor coupled to the other shaft and rotatably housed in the cam housing and having a plurality of plunger chambers formed in an axial direction; and a return spring pressed against each of the plurality of plunger chambers. A plurality of plungers that are received and reciprocally housed and that are driven by the cam surfaces when the two shafts rotate relative to each other; suction and discharge holes that are formed in the rotor and communicate with the plunger chamber; The rotor is slidably in contact with the end surface of the rotor and is positioned in a predetermined relationship with the cam housing. And a valve body having a plurality of suction ports acting as discharge valves and discharge ports formed on the surface, and means for generating flow resistance by the flow of discharge oil by driving the plunger; rotation of both shafts In a hydraulic power transmission joint that transmits torque according to a speed difference, a communication groove that is provided on a rear surface of the valve body that does not form an intake port and a discharge port and that communicates with each of the discharge ports, and the rear surface It is provided with a lid member provided in close contact and a flow resistance generating means provided between the communication groove or the discharge port and the low pressure chamber.

In this hydraulic power transmission joint, the initial torque is increased, the torque is transmitted to FR at a low speed such as when the vehicle starts on a low μ road and a differential starts to be generated, slip is prevented, and running stability of the vehicle is stabilized. I try to secure the sex. In order to increase the initial torque, a check ball 52 is provided in the orifice 51 as shown in FIG.

In FIG. 6, reference numeral 53 denotes a rotary valve as a valve element, and the rotary valve 53 is provided with a discharge port 55, a communication groove 54 communicating with the discharge port 55, and an orifice 51 communicating with the discharge port 55. ing. A check ball 52 pressed by a spring 57 is seated on a valve seat 56 on the outlet side of the orifice 51. Reference numeral 58 is a plug, and 59 is a communication hole communicating with the low pressure side.

The torque characteristic of this joint is shown in A of FIG. 7, and the torque is higher than the normal characteristic B by an amount indicated by C and D.

[0006]

[Problems to be solved by the device]

 However, in such a conventional hydraulic power transmission joint, there is a problem that the check ball is in the flow path and the torque characteristic pulsates. In addition, when the vehicle speed is high or the differential range is low, and it is preferable that the torque is small in the area indicated by E in FIG. 7, the torque increases, fuel consumption deteriorates, and a tight corner braking phenomenon occurs. There was a problem.

The present invention has been made in view of such conventional problems, and a band brake is provided on the outer periphery of the rotor to control torque characteristics to prevent pulsation of the torque characteristics and to reduce fuel consumption. The purpose of this is to prevent the deterioration of tires and the occurrence of tight corner braking phenomena.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a hydraulic pump provided between input / output shafts that can rotate relative to each other, and driven by differential rotation of the both shafts; and a flow resistance provided at an outlet of the hydraulic pump. In a hydraulic power transmission joint that includes a generating unit and that transmits torque according to a rotational speed difference between the two shafts, a band brake is provided on an outer periphery of a rotor connected to one of the input / output shafts, The housing connected to the other of the input / output shafts is provided with a pin for pressing the end of the band brake and a spring for urging the pin.

[0009]

[Action]

 When the cam housing and rotor are not differential, the spring presses the end of the band break with a pin, and the band brake tightens the outer circumference of the rotor. As a result, when the rotation of the main body is small, the initial torque can be secured when the differential is started at the time of transmission and at an extremely low speed, and the maneuverability at the time of starting can be improved.

When the vehicle speed exceeds a certain value, centrifugal force acts on the band brake, and oil is collected in the space of the recess of the band brake. Therefore, the band brake stores the pin against the spring. It is pushed into the hole, spreads outward, and comes out of contact with the rotor. In this way, a low torque can be obtained in the differential region at a certain speed or higher, fuel consumption can be improved, and the occurrence of a tight corner braking phenomenon can be prevented.

Further, since it is not necessary to provide a check ball in the oil passage, it is possible to prevent the pulsation of the torque characteristic.

[0012]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 are views showing an embodiment of the present invention. First, the structure will be described. In FIG. 1, reference numeral 1 denotes a cam having a cam surface 2 having two or more ridges on its inner surface. The cam 1 is connected to an output shaft (not shown) and rotates integrally with the output shaft. To do. The cam 1 is fixed to the cam housing 4 by the welded portion 3, and the cam 1 rotates integrally with the cam housing 4.

Reference numeral 5 denotes a rotor rotatably housed in the cam housing 4. The rotor 5 is coupled to the input shaft 6 and rotates integrally with the input shaft 6. A plurality of plunger chambers 7 are formed in the rotor 5 in the axial direction, and a plurality of plungers 8 are slidably accommodated in the plunger chamber 7 via return springs 9. Further, the rotor 5 is formed with a plurality of suction / discharge holes 10 so as to communicate with the respective plunger chambers 7.

Reference numeral 11 denotes a rotary valve having a suction port, a suction passage, and a discharge port 14 (not shown) formed on the front surface thereof, and a communication groove 15 communicating with each of the discharge ports 14 is formed on the back surface of the rotary valve 11. There is. A lid member 16 is provided in close contact with the back surface. An orifice (flow resistance generating means) 17 is formed in the discharge port 14.

Further, the rotary valve 11 has a positioning projection 19 that engages with a notch 18 formed in the inner circumference of the cam housing 4. The rotary valve 11 constitutes a timing member that determines the opening / closing timing of the intake / discharge hole 10, and the notch 18 and the protrusion 19 constitute a positioning mechanism that regulates the position correlation between the cam 1 and the rotary valve 11.

When the plunger 8 is in the intake stroke, the intake port of the rotary valve 11 and the intake / discharge hole 10 of the rotor 5 communicate with each other, and the orifice 17, the intake port, the intake passage, and the intake / discharge hole of the rotor 5 are connected. Oil can be sucked into the plunger chamber 7 through 10. When the plunger 8 is in the discharge stroke, the relationship is the reverse of the suction stroke, and the suction / discharge hole 10 of the rotor 5 communicates with the communication groove 15 via the discharge port 14 of the rotary valve 11.

Reference numeral 20 is a bearing retainer that rotates integrally with the cam housing 4, and supports the input shaft 6 via a bare ring 21. A needle bearing 22 is interposed between the bearing retainer 20 and the rotary valve 11, and the friction torque on the needle bearing 22 side is set to be smaller than the friction torque between the rotor 5 and the rotary valve 11. There is. Therefore, when the direction of the differential rotation changes, the rotary valve 11 circulates together with the rotor 5, rotates until the positioning projection 19 of the rotary valve 11 hits the notch 18 of the cam housing 4, and then becomes integral with the cam housing 4. To rotate. As a result, the intake / discharge hole 10 is forcibly opened / closed at a predetermined timing even during normal rotation or reverse rotation.

An oil seal 23 is provided between the bearing retainer 20 and the input shaft 6, and an accumulator piston 24 for sucking thermal expansion of oil is slidably housed inside the input shaft 6. ing. Reference numeral 25 is a retainer for preventing infiltration of muddy water into the accumulator chamber. As shown in FIG. 1 and FIG. 2, a band brake 26 is provided on the outer periphery of the rotor 5, and a pin 29 housed through a spring 28 in a housing hole 27 formed in the cam housing 4 ends the band brake 26. 26A is pressed.

Thereby, the initial torque is secured. The weight of the band brake 26 itself is heavy, and the cross section is formed into a substantially concave shape so that the oil is retained in the space 30 inside. When the rotation speed reaches a certain level, the band brake 26 expands outward due to the centrifugal force and comes out of contact with the rotor 5. In addition, 31 and 32 are snap rings, 33 is an oil supply hole, 34 is a needle bearing, and 35 and 36 are O-rings.

Next, the operation will be described. When there is no rotation difference between the cam 1 and the rotor 5, the plunger 8 does not operate and torque is not transmitted. At this time, the plunger 8 is pressed against the cam surface 2 by the return spring 9. Next, when a rotation difference occurs between the cam 1 and the rotor 5, the plunger 8 in the discharge stroke is pushed in by the cam surface 2 of the cam 1 in the axial direction.

At this time, since the suction / discharge hole 10 communicates with the discharge port 14, the plunger 8 pushes the oil in the plunger chamber 7 from the suction / discharge hole 10 to the discharge port 14 of the rotary valve 11. The oil pushed out to the discharge port 14 is supplied to the suction port through the communication groove 15 and the orifice 17. At this time, the hydraulic pressure in the communication groove 15, the discharge port 14, and the plunger chamber 7 increases due to the resistance of the orifice 17, and a reaction force is generated in the plunger 8. By rotating the cam 1 against the plunger reaction force, torque is generated, and torque is transmitted between the cam 1 and the rotor 5. Since the discharge port 14 is communicated with the communication groove 15, the hydraulic pressures of all the plunger chambers 7 in the discharge process are equal.

Further, when the cam 1 rotates, an intake stroke occurs, and the intake / discharge hole 10 communicates with the intake port. Therefore, oil in the intake passage is sucked into the plunger chamber 7 via the intake port and the intake / discharge hole 10, The plunger 8 returns along the cam surface 2 of the cam 1. Here, when the rotation of the main body is small, as shown in FIG. 3, the pin 28 is pressed by the spring 28, and the end portion 26A of the band brake 26 is pressed by the pin 29. As a result, the band brake 26 is tightened on the rotor 5 to secure the initial torque as shown in F of FIG. As a result, the maneuverability at the time of starting can be improved.

When the number of rotations of the main body exceeds a certain value (when the vehicle speed exceeds a certain value), a centrifugal force acts on the band brake 26, as shown in FIG. Pushes the pin 29 into the accommodation hole 27 against the spring 28, spreads it outward, and is not in contact with the rotor 5. The torque characteristic at this time is shown by G in FIG. 5, and a low torque is obtained in the region shown by H.

Therefore, it is possible to prevent the deterioration of fuel efficiency and prevent the occurrence of the tight corner breaking phenomenon. Further, unlike the conventional case, since the check ball is not used in the oil passage, the torque characteristic does not pulsate.

[0025]

[Effect of the device]

 As described above, according to the present invention, the brake band is provided on the outer periphery of the rotor and the pin is pressed against the brake band by the spring, so that the initial torque can be secured, the fuel consumption is improved, and the tight corner is improved. It is possible to prevent the occurrence of the braking phenomenon.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a sectional view.

FIG. 3 is an explanatory diagram of a non-differential state

FIG. 4 is an explanatory diagram of differential operation.

FIG. 5 is a graph showing torque characteristics

FIG. 6 is a sectional view of a conventional rotary valve.

FIG. 7 is a graph showing torque characteristics.

[Explanation of symbols]

 1: Cam 2: Cam surface 3: Welded part 4: Cam housing 5: Rotor 6: Input shaft 7: Plunger chamber 8: Plunger 9: Return spring 10: Suction / discharge hole 11: Rotary valve 14: Discharge port 15: Communication groove 16: Lid member 17: Orifice 18: Notch 19: Protrusion 20: Bearing retainer 21: Bearing 22: Needle bearing 23: Oil seal 24: Accumulator piston 25: Retainer 26: Band brake 26A: End 27: Storage hole 28: Spring 29: Pin 30: Space part 31, 32: Snap ring 33: Oiling hole 34: Needle bearing 35, 36: O-ring

Claims (2)

[Scope of utility model registration request] 1. A hydraulic pump provided between relatively rotatable input and output shafts and driven by differential rotation of the both shafts; and a flow resistance generating means provided at an outlet of the hydraulic pump, In a hydraulic power transmission joint that transmits torque according to a rotational speed difference between both shafts, a band brake is provided on the outer circumference of a rotor connected to one of the input / output shafts, and is connected to the other of the input / output shafts. A hydraulic power transmission joint characterized in that a housing is provided with a pin for pressing the end of the band brake and a spring for urging the pin. 2. The hydraulic power transmission joint according to claim 1, wherein the band brake has a substantially concave cross section so that oil is retained between the band brake and the rotor.