DD150099A5 - APPARATUS FOR ADJUSTING THE DEAD GAME - Google Patents

Abstract

1. An automatically acting mechanism for setting and adjusting the lost motion (a) of a hydraulically actuated device (13-18), in particular a clutch or a brake, to a predetermined value, characterized by a pressure-transfer means (1), which is insertable into the pressure line from the element (12) controlling the device (13-18) to the hydraulic working cylinder (13) of the device (13-18), the cylinder chamber of which presure-transfer means of large cross-section (2, 19, 28) being connectible with the control element (12), and its cylinder chamber of small cross-section (3, 20, 29) being connectible with the hydraulic working cylinder (13), at least one duct (7 ; 21, 25 ; 31) being provided between the two cylinder chambers (2, 3 ; 19, 20 ; 28, 29), which duct is controlled by a valve means (8 ; 22, 26 ; 311, 31), biassed in the closing direction by a spring (9 ; 23, 27 ; 34), in such manner that, in the normal position of the pressure-transfer piston (4, 4" ; 24 ; 33), the duct is closed and, upon presurizing of the pressure-transfer means by the control element (12) and following displacement of the pressure-transfer piston from the normal position over a predetermined distance (b, b', b"), which is proportional to the predetermined value of the lost motion (a), the duct is opened and is then closed upon relaxation of pressure when the presure-transfer piston (4, 4" ; 24, 33) is removed from its normal position over the predetermined distance (b, b', b").

Description

12 858 56

Oil device for adjusting the dead game

Field of application of the invention:

The invention relates to a device for adjusting the dead clearance, in particular for the automatic on or »readjustment of operated with hydraulic working cylinders constructions, such as clutches.

Characteristic of the known technical solutions:

In some of the hydraulically operated structures, it is due to puncture safety and other reasons appropriate, possibly indispensable necessary that the operated structure is free of play regardless of wear or the dead game is kept at a constant value. The latter requirement exists in particular for clutches and brakes «

In order to solve this problem, several constructions have been worked out. However, these make adjustments without exception using mechanical elements. Such apparatuses are described for example in HU-PS I69 345 »DT-PS 1 289 689 and US-PS'η 4 057 134 and 4 057 135« The common disadvantage of these constructions is that they - act mechanically - even subject to wear and as a result also changes their mode of action. Moreover, they are complicated and therefore expensive to manufacture.

Object of the invention

The aim of the invention is to provide a hydraulic device for adjusting and adjusting dead play in hydraulically operated structures, and to eliminate the errors resulting from mechanical solutions.

Explanation of the essence of the invention:

The invention is based on the fact that in hydraulically operated devices at each point of displacement of the operated structure of the associated pressure value is independent of the wear of the construction is constant. "The respective puncture position of the construction can therefore be perceived hydraulically at any moment. A value occurring in the pressure range can therefore be used as a hydraulic signal and used to set the dead time to the prescribed value.

The essence of the invention is that the device has two hydraulic cylinder chambers of different cross-section, each of which is equipped with a sealed piston, the two pistons having a

- 3 -

others are in forced connection. Furthermore, at least one channel is provided, which connects both cylinder chambers and which has a closing element which, against the pressure of a spring of the liquid, clears the way from the space with a smaller cross section into the space with a larger cross section *.

According to the preferred embodiment of the invention, the two cylinder chambers are designed as a stepped cylinder and the pistons are designed as a stepped piston

Furthermore, it is advantageous if the channel connecting the two cylinder chambers is formed in the piston and closed against the space with the larger cross section through the housing or, if necessary, through a valve guided in the housing and loaded by a spring, the spring containing the channel Piston acts.

According to a further preferred embodiment of the invention, both cylinder chambers are connected by two channels, one channel being equipped with a check valve having a flow path in the direction of the space with the smaller cross-section, while the second channel is formed in this check valve and a flow path towards the room with the larger cross-section.

According to a further advantageous embodiment of the invention, at least one opening of the channel connecting the two cylinder chambers is formed in the jacket of the corresponding cylinder chamber, wherein serves as a closing element of the stepped piston, which is loaded by a spring.

The device according to the invention automatically provides the dead clearance of hydraulically operated structures. and steplessly to the desired value. The setting is hydraulic. The parameters of the device do not change during operation, since the change caused by the closure of the individual parts is negligible. The device is simple in construction and therefore easy to manufacture. It also has the advantage that it can be manufactured as a separate unit and retrofitted into existing hydraulic systems ·

Embodiment:

The invention will be explained in more detail with reference to a drawing

Pig »1: shows the coupling system of a force vehicle and the device according to the invention for adjusting the dead play in a schematic representation,

Pig. 2: each show a preferred embodiment. f _orm (Jg ₁ , device _according to the invention.

The cylinder chamber 2 of the device 1 having a larger cross section is connected to the cylinder 12 of the clutch pedal via a pipeline. The cylinder chamber 3 having the smaller cross section is connected via a pipeline to the clutch actuating cylinder 13. The moving in the cylinder chambers stepped piston 4, 4 ¹ is sealed by sealing rings 5 and 6. The cylinder chambers 2 and 3 are connected to each other via the passage 7 guided through the stepped piston channel. The channel is closed by the valve 8, which by the spring 9 against the stepped

piston is pressed. The stop 10 is located at the other end of the valve stem guided in the housing. The stepped piston is held in the basic position by the spring 11. The entire system is filled with liquid.

When the system is retired, the prescribed gap a exists between the clutch bearing 16 and the lifting levers 17 of the clutch. "Upon actuation, liquid flows into the space 2 by pushing the clutch pedal out of the cylinder 12 and moves the stepped piston 4, 4 ^! > the valve 8 follows. The stepped piston with the provisionally closed channel pushes the liquid from the space 3 in the working cylinder 13 »which is released via the push rod 14 and the connecting lever 15 by moving the clutch bearing 16, the clutch, that is disengaged. First, the gap a and the clearance between the transmitting parts disappear. In the actuator pressure builds up, and the clutch is ready for the actual disengagement. As the stop 10 strikes, the stepped piston leaves the valve 8 and the liquid flows out of the cylinder 12 through the channel 7 into the working cylinder. , 'ie the clutch is released and disengaged.

When closing the clutch, the pressure plate and the entire lifting mechanism are pushed back by the clutch springs in the basic position. The liquid is forced back out of the working cylinder 13 into the cylinder 12. As the pressure drops, the stepped piston is pushed by the spring 11 into its basic position. When the pressure plate of the clutch has reached the rubbing plate and this the degree of swelling, the fluid pressure suddenly drops. At the selected and the dimensions of the construction corresponding pressure reaches the

Stepped piston, valve 8, and channel 7 is closed »Thereafter, only a certain amount of liquid is left from the working cylinder by the stepped piston« When the clutch pedal is fully released, the stepped piston returns to its original position. In this case, the gap a assumes a value which is proportional to the displacement b belonging to the closed state of the channel 7. The value of section b is constantj the translations are also constant. Therefore the value of a is constant *

In the embodiment shown in Fig. 2, the two chambers 19 and 20 of the device are connected by two channels * The channel 21 is formed in the stepped piston 24 and closed by a flow · in the direction of the space 20 releasing check valve 22, the a weak spring 23 has ", the channel 25 is formed in the check valve 22 and provided with a flow in the space 19 releasing check valve 26 * The check valve 26 is held by the prestressed spring 27 in the closed state.

The puncture of this embodiment is similar to that already described. Upon release of the clutch, the stepped piston passes into the extreme position indicated by a dashed line. * Upon engagement, the liquid flows through the channel 25 from the working cylinder back into the cylinder 12 (not shown) at a selected pressure, which is certainly greater as the pressure of the spring 18 closes the check valve 26, and the stepped piston 24 returns to its normal position. The gap a is proportional to the portion b 'lying between the two outermost positions of the stepped piston.

In the embodiment according to Pig. 3, the cylinder spaces 28 and 29 are via openings 31; 32 connected by the located in the wall of the cylinder channel 30 with each other. The stepped piston 33 is held by a spring 34 in the basic position.

The puncture is similar to that already described. The channel 30 is opened or closed after the opening or obscuring the opening 31 of the stepped piston itself. The gap a is the displacement between the basic position of the stepped piston and the opening of the opening 31 »d _o h. the section b ' ¹ proprotional «

The embodiments described herein can also be combined, for example, the valve shown in Fig. 2 can be installed in a duct according to Fig. 3. Cylinders and pistons do not necessarily have to be stage cylinders or stepped pistons, two simple cylinders can also be used -

With the device according to the invention, a play-free state can be set. This is possible by suitable choice of the characteristic of the spring, which closes the closing element which closes the return flow from the smaller space to the larger one. Also with b = 0 (appropriate construction) no play is present.

With the device according to the invention, the dead play can be automatically adjusted and kept at the prescribed value. Because the apparatus has no fast wearing parts, their parameters in the course of operation does not change, d _e h * the apparatus is more perfect than the previously known solutions. The pros

- 8th

Direction can be designed as a separate unit and mounted on the control of a hydraulic system or to the working cylinder «, The device can be retrofitted in existing systems.

Claims (1)

invention claim Device for adjusting dead play, in particular for automatically adjusting and adjusting the play of hydraulically operated structures, such as clutches to the prescribed value, characterized in that it comprises two hydraulic cylinder chambers of different cross section, each having a sealed piston, which are in forced connection with each other, wherein at least one channel connecting both cylinder chambers is provided, which is provided with at least one closing element, which releases the path for the working fluid from the space with a smaller cross section in the space with a larger cross section against the force of a prestressed spring , 2 "device according to item 1, characterized in that the two cylinder chambers are designed as a stepped cylinder and the two pistons as stepped pistons. 3 «Device according to item 1 or 2, characterized in that the two cylinder chambers (2, 3) connecting channel (7) in the piston (4, 4 ') formed and against the space with the larger cross section through the housing of the apparatus itself or, if necessary, is closed by a guided in the housing and loaded by a spring valve (8) and a spring (11) acting on the piston having the channel. 4 »device according to item 1 or 2, characterized in that both cylinder chambers (19, 20) by two channels (21, 25) are interconnected and the one channel (21) by a in the direction of the space with the smaller cross-section a free Flow enabling kickback - 10 Valve (22) is provided, while the second channel (25), which ensures a flow in the direction of the space with the larger cross-section, formed in this check valve (22) and a by a spring (23) biased check valve (26) is provided , Apparatus according to item 1 or 2, characterized in that at least one opening (31) of the channel (30) connecting the two cylinder chambers (28, 29) is formed in the mantle of the corresponding cylinder space and closes it as the closing element of the corresponding cylinder chamber with the spring (34) loaded piston (33) is used * For this 1 page drawings - 11 -