DE2328735B2 - VALVE ACTUATION FOR AIR BRAKE VALVES IN MOTOR VEHICLES - Google Patents

Description

45

The invention relates to valve actuation, in particular Pedal, for air brake valves of motor vehicles, v / elches with a preferably opposite a highly progressive force <. movable actuating tappet cooperates.

Valves of the above genus are predominant Used in braking systems in which the tus-controlled maximum brake pressure exceeds the maximum The storage pressure in the storage tanks of the system corresponds to the relatively large storage tanks Episode. Efforts are being made to save the storage container on the vehicle to save space Decrease, which, however, increases the accumulator pressure compared to the permissible modulated Maximum brake pressure is connected to keep the required air volume available place.

The invention is based on the object of using simple means and without impairing the prescribed and desired braking effect, ⁶ S, in particular with regard to the response times and the fine-grained or sensitive brake actuation, to prevent the vehicle from overrunning and thus overstressing the braking elements.

This object is erfindungsgemilß achieved in that in the active compound pedal Betütigungssiößel _jt a "*" force biased Oruckbeßrenzungsglied is zwiscnengesehaltet _einar determined.

Elements preloaded with a certain force, which are integrated into the connection of the brake pedal actuating devices are switched from the ■ oiSs l "SÄi US-PS 1645 846, US-PS 18 24 725 and from DT-AS12 44 505 known.

GB-HS 14 05 548 discloses an actuating device in which in the transmission or connecting elements of a pedal-operated master brake cylinder or a brake valve a rubber element is connected, which is designed according to this invention as a cutter. The shear shape of this Rubber element should give the driver a better feeling for the valve actuation.

The invention in US-PS 16 45846 has to Task to limit the braking force to be applied to the brake cylinder by means of a spring installation means that the brake pedal is forced genuinely on the floor before the wheels block while at the same time the spring exerts an even pressure on the brake for as long the pedal is depressed.

In the device from US-PS 58 24 725 is in Connection length between brake pedal and wheel brakes arranged a device soft by means of a spring by the driver when the brake is applied pedal pressure to be applied from the beginning of the braking process until the vehicle comes to a standstill at the same time holds, d. H. enables sensitive braking.

The DT-AS 12 44 505, on the other hand, shows one between the movement of the plunger of a control valve serving lever and the plunger itself arranged spring whose task it is to interact with other devices to give the driver a sense of the force with which the brakes are applied by the counterpressure created by the partial compression of the spring is perceived by the driver

^Wl ßei GB-PS 14 05 548, US-PS 18 24 725 and DT-AS 12 44 505 are F.inrichter for sensitive braking of a vehicle, whereby in GB-PS 14 05 548 the shear effect of a rubber element , in US-PS 18 24 725 afflicted with great safety and wear risks, mt emr spring cooperating lever device biiden the characteristics and in DT-AS 12 44 505 the spring arranged between the pedal and tappet, in cooperation with the valve actuation and the pressure conditions prevailing in the valve, with regard to sensitive braking, provide a partial amount »

The US-PS 1645 846 Defass itself with a pressure limiting device, which consists of a pedal device cooperating between levers and spring. Here, however, they meet in relation to you US-PS 18 24 725 mentioned negative features, namely great safety and wear risks, in to an even greater extent, since these risks are much higher with a pressure-limiting device are evaluating. In addition, the pressure level is a pressure-limiting device consisting of reversing levers not precisely adjustable due to the play in the joints.

In the pressure limiting device according to the invention guide the pedal and the actuating foot up

3 4

carries a valve element 16 to control a predetermined maximum and at its upper end,

Brake pressure together from an actuation stroke, which together with a valve seat 17 of the control piston

When this pressure or the corresponding 12 is reached, an outlet valve 16, Yl s «as together with

the progressive reaction force acting on the pedal to a valve seat 18 fixed to the housing, an inlet valve> 6, \ t>

this reaction force or the maximum 5 forms.

Brake pressure corresponding bias of the Druckbe- Between the step plate 2 and the lever 3 is a

limit member overcome so that the pedal is arranged without a preloaded pressure limiting spring 19,

further displacement of the actuating plunger relative to which encloses a bolt 20, which with the

this is moved further, a further increase in the footplate 2 is firmly riveted to its other end

Brake pressure is thus prevented and the essentially OK penetrates the bolt 20 with play <ine opening 21 of the

higher reservoir pressure shut off. Lever 3, which with the help of a on the bolt 20

To the pedal a nut 22 set and secured to the maximum brake pressure, the lever 3 in

corresponding, defined actuation end position to its preloading the pressure limiting spring 19

give is according to an advantageous embodiment of the shackle position holds. In addition, the bolt is 20 in

Operating stroke of the pedal by a stop i ₅ near the lever 3 and between this and the

limited, which is due to the bias of the step plate 2 with a the on ^ ärtsbewegung of the

Pressure limiting member specific actuating lever 3 limiting end stop 23 is provided,

adjustment of the pedal is adjustable. Opposite the bolt 20 is a stop bolt 24

In a further embodiment, the restraint is carried out in the base plate 5, which in combination

Pressure limiting member on the one hand by the step _{platform 20} effect with a counter-stop 25 on the bolt 20

fite of the pedal and on the other hand limited by a common operating stroke of the pedal 1, and its height

[ Can be pivoted with the pedal and relative to it in such a way that both stops 24, 25

ren, directly act on the actuating plunger, when the preload of the spring 19 is straight

the lever, wherein the lever is overcome relative to its one.

Footplate of the pedal possible inward movement 25 The operating principle of the device is as follows:

limiting end stop is assigned. When you press the pedal I, the footplate will be

Way, in the event of failure or breakage of the 2 and the lever 3 together moved inwards, whereby

Pressure limiting member a sudden, unintentional the actuating which is in contact with the lever 3

prevents the brake pressure from falling. tappet 7 via the graduated spring 13 the control piston

An embodiment of the invention is subsequently moved downwards. In this way, first of all, the

explained in more detail with reference to the drawing. It shows exhaust valve 16, 17 closed and then the intake valve

F i g. 1 a brake actuation device for a valve 16, 18 opened so that the supply connection 10

Eir.kreisig brake valve shown in simplified form in the compressed air in the brake connection 11

Cut and pour over. The brake pressure builds up accordingly

F i g. 2 shows the pressure profile of the controlled braking 35 corresponding to the curve profile a according to FIG. 2 in the

pressure over the actuation path at the valve according to the brake cylinders. At the same time it builds up under the

Fig. I. Control piston 12 a pressure on which the control piston

The brake actuating device consists of a ben 12 against the craft of the longitudinal spring 13

Pedal 1, which moves a tread plate 2 and a lower one at the top, up to both sides of the control piston 12

Has lever 3, both of which arise on a common 40 balance of forces. In this situation they are

Axis 4 pivotable on a base plate 5, inlet valve 16, 18 and the / Vuslaßventii 16, 17

are stored. The unactuated end position of the pedal 1 is closed.

is activated by an adjustable stop screw 6

determined, which is attached to the base plate 5. Moved down until the bias of the

The lever 3 has direct contact with a pressure limiting spring 19 which is overcome. at Actuating plunger 7, which is axially displaceable on further actuation of the step plate 2, this moves Base plate 5 out and provided with a protective sleeve 8 only by compressing the pressure relief is. spring 19 with the bolt 20 down until its

A: n the lower end of the base plate 5, a stop 25 touches the stop pin 24. These

Schematically shown, single-circuit compressed air brake 50 relative movement of the step plate 2 with respect to the

arranged valve 9, which a supply connection 10 stationary lever 3 happens without essential

and a brake connection 11. In its increase in strength and without any substantial increase in the

Housing is a sealed guided control piston 12 brake pressure. These conditions are due to the

arranged », which is reproduced via a highly progressive, graduated curve b. the

spring 13 displaced by the actuating plunger 7 55 bias of the pressure relief spring 19 is determined

are '* an and the ncrmaierweise by a see thus the maximum height of the controlled braking

innfhdlb of the housing supporting return spring 14 pressure at the output terminal Ii. during the am

ίη is held in an upper end position. Since, input port 10 pending supply pressure is essential

Compressed air brake valve 9 also has a tax borrowed higher or can be higher,

socket 15 which is open to the atmosphere at the bottom 60

1 sheet of drawings

Claims (7)

! Patent claims: 1. Valve actuation, in particular pedal, for air brake valves of motor vehicles, which cooperates with an actuating tappet which can be moved preferably counter to a highly progressive force, characterized in that that in the operative connection pedal (1) - actuating plunger (7) with a certain force Pre-tensioned pressure limiting element (O) between-> ° schaltel is. 2. Valve actuation according to claim I, characterized in that the pressure limiting member tl9) is designed as a helical spring, 3. Valve actuator according to claim 1, characterized in that the restraint of the pressure limiting member (19) on the one hand by the tread plate (2) of the pedal (1) and on the other hand by a together with the pedal and relative to this pivotable, directly the actuating tappet (7) acting on lever (3) takes place. 4. Valve actuator according to claim 3, characterized in that the lever (3) has a relative assigned to the step plate (2) of the pedal (1) possible inward movement limiting end stop (23) is. 5. Valve actuation according to claim 1, characterized in that the actuation stroke of the pedal (!) Can be limited by a stop (24), which is acted upon by the bias of the pressure limiting member (19) certain operating position of the pedal is adjustable. 6. Valve actuation according to claims 3 and 5, characterized in that the P? .Dal (1) has a fixed with its step plate (2) connected bolt (20) which penetrates the lever (3) with play, holds it in its heel position and forms a counter-stop (25) for the stop (24). 7. Valve actuation according to claims 4 and 6, characterized in that the end; nschmg (23) for the lever (3) is attached to the bolt (20).