JPH0133868Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a negative type hydraulic traveling clutch.

Conventionally, when a hydraulic clutch is used in a traveling system of a tractor or the like, whether the clutch is a positive type or a negative type, there has been a problem that when the clutch is operated, the tractor suddenly starts without being brought into a half-clutch state. In particular, a piston body provided on the driven side facing the clutch plate interposed between the drive shaft and the driven shaft is moved forward toward the clutch plate by the force of the bullet and retreated by the hydraulic pressure from the pressure oil chamber. In a negative wet type hydraulic multi-disc clutch which is designed to intermittent power, it is not possible to bring the clutch into a half-clutch state even if a pressure increase valve or a throttle is provided in the hydraulic circuit to the pressure oil chamber. For example, if only a restrictor is provided in the hydraulic circuit, when the clutch is switched from "disengaged" to "engaged", the forward movement of the piston body will be slow, resulting in a delay in the time from the clutch operation to the tractor starting. However, there is a drawback that a half-clutch state, which smooths out the torque transmission characteristics, cannot be created.

The present invention was devised in order to eliminate these drawbacks in view of the above-mentioned actual situation, and the piston body has a plurality of small pistons that protrude and retract from a spring chamber provided in the piston body toward the clutch plate. The small piston is biased toward the clutch plate through a spring provided in a spring chamber, and the spring chamber is communicated with a pressure oil chamber through a constriction, so that a negative Even if the wet type hydraulic clutch is
The object of the present invention is to provide a hydraulic traveling clutch with smooth switching operation that can reliably prevent a sudden start of the tractor due to clutch operation by causing a half-clutch state when switching from "continue" to "continue". It is.

The structure of the present invention will be described with reference to an embodiment shown in the drawings. Reference numeral 1 denotes a hydraulic clutch used in the traveling system of a tractor, and the hydraulic clutch 1 is located behind a drive shaft 2 and coaxially It is splined concentrically to the outer periphery of a driven shaft 3 disposed at the core via a hub 4. Reference numeral 5 denotes a cover attached to the rear end of the drive shaft 2 facing the hydraulic clutch 1, and between the cover 5 and the hydraulic clutch 1, inner plates 6 and outer plates 7 are arranged alternately. A clutch plate 1' is interposed. Reference numeral 8 denotes a piston body that slides back and forth toward the clutch plate 1', and a disc spring 10 is interposed between it and a holder 9 fixed to the rear of the hydraulic clutch 1. Due to the bias, the piston body 8 slides forward, and the clutch plate 1'
Press to set clutch 1 to "continue". Reference numeral 11 denotes a cylinder along which the piston body 8 slides, and the cylinder 11 and the piston body 8 form a pressure oil chamber a. The piston body 8 is moved backward against the urging force of the disc spring 10 by the pressure oil sent through the clutch 1, thereby disengaging the clutch 1.

In the piston body 8, a plurality of spring chambers 12, 12, . piston 1
3, 13, . . . are respectively fitted so as to be freely protrusive and retractable toward the inner plate 6. Reference numeral 14 denotes a spring installed in the spring chamber 12 at the base end side of the small piston 13, and the small piston 13 is elastically supported so as to protrude toward the clutch plate 1' due to the bias of the spring 14. When the piston body 8 is in the "connected" state in contact with the clutch plate 1', the small piston 13 resists the spring 13 and moves into the spring chamber 12.
In the "disconnected" state in which the piston body 8 is retracted, it protrudes to a position separated from the clutch plate 1' with a slight gap.

The spring chamber 12 has a small diameter constriction part 1.
It is connected to the pressure oil chamber a via 5.

In the above configuration, the hydraulic clutch 1
In order to turn off the pressure oil, first, pressurized oil is fed into the pressure oil chamber a from the oil passage b leading to the oil tank on the aircraft side through the oil groove c, but the piston body 8 The small piston 13 moves back against the clutch plate 1'
As the piston body 8 retreats, the small piston 13 protrudes while remaining in contact with the hydraulic clutch plate 1'. can be reliably rejected. Next, in order to change the hydraulic clutch 1 from the "disconnected" state to the "engaged" state, the pressure oil in the pressure oil chamber a is communicated with the oil tank, and the pressure in the pressure oil chamber a becomes 0. The piston body 8 moves forward toward the clutch plate 1' by the force of the disc spring 10, and the small piston 13 protruding from the piston body 8 first comes into contact with the clutch plate 1', and as the piston body 8 moves forward, the spring 14 Immerse yourself while compressing. For this reason, the pressure force with which the small piston 13 presses against the clutch plate 1' gradually increases.
The hydraulic clutch 1 can be in a half-clutch state. The small piston 13 is connected to the spring chamber 14.
The hydraulic clutch 1 can be reliably engaged at the position where the piston body 8 presses the clutch plate 1' under the force of the disc spring 10.

Since the spring chamber 12 is connected to the pressure oil chamber a through the small-diameter constriction part 15, when the small piston 13 retracts while compressing the spring 14, the pressure oil in the spring chamber 12 flows into the constriction part. 15 to the pressure oil chamber a, a back pressure is generated in the spring chamber 12. Therefore,
The small piston 13 presses with a stronger force than when pressing the clutch plate 1' with only the bias of the spring 14, so it can change the hydraulic clutch 1 from "disengaged" to "engaged".
The torque transmission characteristic when switching to the clutch becomes smoother, and the clutch can be switched smoothly.

In short, the present invention provides a piston body on the driven side opposite to the clutch plate interposed between the drive shaft and the driven shaft, moves the piston body forward toward the clutch plate side by the urging force of the bullet, and pressurizes the piston body. In a wet hydraulic multi-disc clutch that is retracted by hydraulic pressure from an oil chamber to intermittent power, the piston body includes:
A plurality of small pistons are provided that protrude and retract toward the clutch plate from a spring chamber provided in the piston body, and the small pistons are biased toward the clutch plate via a spring provided in the spring chamber, and the spring Since the chamber communicates with the pressure oil chamber through the throttle, when the piston moves forward toward the clutch plate due to the force of the bullet, the small piston first presses the clutch plate and resists the spring. Since the piston body comes close to the clutch plate while being immersed in the chamber, even with a negative type hydraulic multi-disc clutch, the clutch can be left in a half-clutch state when switching from the "disengaged" state to the "engaged" state. This makes it possible to reliably prevent a tractor or the like from suddenly starting due to clutch operation. When the small piston moves into the spring chamber against the spring, back pressure is generated in the spring chamber that communicates with the pressure oil chamber through the throttle, making the torque transmission characteristics even more gradual and smooth. This provides extremely useful practical effects such as being able to perform clutch switching operations.

[Brief explanation of the drawing]

The drawings show an embodiment of the hydraulic traveling clutch according to the present invention, and FIGS. 1A and 1B are cross-sectional views showing the clutch in the "disengaged" and "engaged" states, respectively. In the figure, 1 is a hydraulic clutch, 1' is a clutch plate,
8 is a piston body, 10 is a disc spring, 12 is a spring chamber, 13 is a small piston, 14 is a spring, 1
5 is a constriction part.

Claims (1)

[Scope of utility model registration request] A piston body is provided on the driven shaft side opposite to the clutch plate interposed between the drive shaft and the driven shaft, and the piston body is advanced toward the clutch plate side by the bias of the bullet,
In a wet hydraulic multi-disc clutch which is retracted by hydraulic pressure from a pressure oil chamber to "intermittent" power, the piston body has a spring chamber provided in the piston body that protrudes and retracts from a spring chamber provided in the piston body toward the clutch plate. A plurality of small pistons are provided, and the small pistons are biased toward the clutch plate via a spring provided in a spring chamber, and the spring chamber is communicated with a pressure oil chamber via a constriction portion. Hydraulic travel clutch featuring: