JPH0530569U - Fluid joint structure of fluid coupling - Google Patents

Abstract

(57) [Summary] (Modified) [Objective] The present invention relates to an orifice structure of a fluid coupling used in a hydraulic differential limiting device, which can reduce the processing cost and easily expand the tuning range. An object of the present invention is to provide an orifice structure of a fluid coupling that can be used. A spool 23 having a groove 23B having a predetermined groove width and a variable groove depth is slidably provided in a rotor 21.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an orifice structure of a fluid coupling used in a hydraulic differential limiting device.

[0002]

[Prior Art]

 As a conventional orifice structure of this type of fluid coupling, there are, for example, those shown in FIGS. 5 and 6, reference numeral 1 denotes a right axle shaft, a cam housing 2 having a cam surface 2A formed on an inner surface thereof is fixed to the right axle shaft 1, and the cam housing 2 rotates integrally with the right axle shaft 1. To do.

A rotor 4 is fixed to a left axle shaft (not shown), and the rotor 4 rotates integrally with the left axle shaft. A plurality of plunger chambers 5 are formed in the rotor 4 in the radial direction, and a plurality of plungers 6 are slidably accommodated in the plunger chamber 5. A suction passage 7 communicates with the plunger chamber 5, and a suction valve 8 made of a check ball is provided in the suction passage 7.

A discharge passage (oil passage) 9 communicates with the plunger chamber 5, and the discharge passage 9 is formed in the rotor 4. A fixed member 10 is fixed in the rotor 4, and an orifice 11 communicating with the discharge passage 9 is formed in the fixed member 10. The orifice 11 communicates with the hydraulic chamber 12. Reference numeral 13 is a spool slidably accommodated in the fixed member 10. The spool 13 is pressed by the push rod 14 to move, thereby changing the orifice area (see FIG. 7). .. The arrow A indicates the flow of oil.

However, since the diameter of the orifice 11 is small, the width of the orifice 11 is set to several hundreds of microns in order to make the spool 13 stroke several hundreds of microns and obtain the differential limiting torque characteristics in the range shown in FIG. It must be managed in units (see Figure 8).

[0006]

[Problems to be solved by the device]

 However, in such a conventional fluid coupling orifice structure, the orifice must be formed with a predetermined accuracy by drilling, which is not easy to process, the cost increases, and the tuning range is limited. There was a problem that it could not be easily expanded.

The present invention has been made in view of such conventional problems. By forming a groove on the spool, the processing cost can be reduced and the tuning range can be easily expanded. It is an object of the present invention to provide an orifice structure for a fluid coupling that can be used.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a fluid coupling for controlling a transmission torque by generating a flow resistance by driving a plunger by a rotational speed difference between a rotor having an oil passage and a cam housing. A spool having a groove having a predetermined groove width and a variable groove depth is slidably provided on the.

[0009]

[Action]

 In the present invention, the orifice formed in the fixing member fixed in the rotor is abolished, and a spool having a groove having a predetermined groove width and a variable groove depth is slidably provided in the rotor. The stroke changes the orifice area. In contrast to the conventional orifice processing that was hole processing, in the present invention, since the spool groove is processed by the outer diameter, the processing becomes easier and the cost can be reduced.

Further, the tuning range can be easily changed by changing the groove width and the groove depth.

[0011]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 are views showing an embodiment of the present invention. In FIG. 1, 21 is a rotor fixed to a left axle shaft (not shown), and the rotor 21 rotates integrally with the left axle shaft.

A plurality of plunger chambers (not shown) are formed in the rotor 21 in the radial direction, and a plurality of plunger chambers (not shown) are slidably accommodated in the plunger chamber. The plunger is driven by the difference in rotation between the rotor 21 and a cam housing (not shown) to generate flow resistance. Reference numeral 22 is an oil passage formed in the rotor 21, and the oil passage 22 communicates with a plunger chamber (not shown).

A spool 23 is slidably accommodated in the rotor 21, and a stroke of the spool 23 is made by a push rod 24 as shown by an arrow B. A stopper 23A is integrally formed on the spool 23, and the stopper 23A abuts a step portion 21A formed on the rotor 21 and also a snap ring 25 inserted in the rotor 21. Reference numeral 26 indicates a hydraulic chamber.

As shown in FIG. 2, a key 27 is inserted between the rotor 21 and the spool 23, and the key 27 prevents the spool 23 from rotating. A groove 23B serving as an orifice is formed in the spool 23, and the groove 23B has a groove width t and a groove depth d. As shown in FIG. 4, the groove depth d is formed so as to increase toward the front end portion of the spool 23. Further, as shown in FIG. 3, the groove depth d may be formed so as to gradually increase. Further, the outer diameter φD may be changed by changing the angle θ of the groove 23B.

In FIG. 1, L1 or L2 indicates an orifice opening, and the orifice area is set by t × L. The orifice area is changed by making the stroke of the spool 23. The oil is pushed out of the oil passage 22 through the orifice into the hydraulic chamber 26, and the flow resistance of the orifice at this time raises the oil pressure in the oil passage 22 and the plunger chamber, and a reaction force is generated in the plunger. A torque is generated by rotating the cam housing against the plunger reaction force, and the torque is transmitted between the cam housing and the rotor 21.

Conventionally, the orifice is formed in the fixing member by hole processing, but in the present embodiment, since the groove 23B is formed in the spool 23 by outer diameter processing, the orifice processing becomes easy, The cost can be reduced. Further, the tuning range can be easily changed by making the groove width t and the groove depth d of the groove 23B variable.

[0017]

[Effect of the device]

 As described above, since the groove having the predetermined groove width and the variable groove depth is set as the orifice in the spool, the machining is facilitated and the cost can be reduced. Also, the tuning range can be easily changed.

[Brief description of drawings]

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

FIG. 2 is a side view of the present invention.

FIG. 3 is a diagram showing a spool.

FIG. 4 is a diagram showing another spool.

FIG. 5 is a partial cross-sectional view showing a conventional example.

FIG. 6 is a sectional view showing a conventional example.

FIG. 7 is a sectional view of a main part showing a conventional example.

FIG. 8 is a diagram showing a conventional orifice.

FIG. 9 is a graph showing torque characteristics

[Explanation of symbols]

 21 ... Rotor 21A ... Step 22 ... Oil passage 23 ... Spool 23A ... Stopper 23B ... Groove 24 ... Push rod 25 ... Snap ring 26 ... Hydraulic chamber 27 ... Key

Claims (1)

[Scope of utility model registration request] 1. A fluid coupling in which a plunger is driven by a rotational speed difference between a rotor having an oil passage formed therein and a cam housing to generate a flow resistance to control a transmission torque. An orifice structure of a fluid coupling characterized in that a spool having a groove having a groove depth is slidably provided to perform an orifice operation.