SE415872B - ARRANGEMENTS TO LOCATE A VEHICLE COUPLE - Google Patents

Description

jeovzšo-6 known arrangement is a coupling affecting the lever connected to a piston in a compressed air cylinder. When the clutch pedal is depressed, the compressed air cylinder is activated, whereby the piston in it performs the actual disengagement work. The piston is then arranged to co-operate with interlocking means which, regardless of whether the clutch pedal is released prematurely, keep the clutch in its disengaged position until the shifting process is completed. The interlocking means then consist of an interlocking valve which is located in the compressed air line to the compressed air cylinder and of a sensing means which senses the gear position and in dependence thereon controls the interlocking valve. When the gear is engaged, the interlock valve assumes a venting position, whereby the compressed air in the compressed air cylinder is released freely to the surroundings at the same time as the connection to the vehicle's compressed air system is blocked. During the shift process, the interlock valve assumes a position which allows connection between the vehicle's compressed air system and the compressed air cylinder, the compressed air cylinder being completely filled with compressed air which gives its piston a maximum deflection and keeps the clutch in a disengaged position during the shift process.

Such known arrangements with coupling interlock in a compressed air circuit are preferably suitable for coupling systems with manual settings of coupling winches depending on the wear of the coupling lamellae.

For heavier vehicles, however, it is only common to use servo units for clutch operation with automatic setting of the clutch clearance depending on the wear of the clutch lugs. Such a servo unit comprises a compressed air cylinder, the piston of which is connected to the clutch lever via a push rod. When activating the servo unit, the piston performs a movement with a stroke corresponding to the stroke of the clutch pedal. After activation, the piston returns to a rest position under the influence of spring force. Said rest position of the piston will move as the clutch slats wear, while the stroke of the piston when activating the clutch pedal will remain unchanged. This means that the compressed air cylinder must be designed with a stroke that is significantly greater than a maximum pedal stroke.

When using such a servo unit, coupling interlock by supplying compressed air to the compressed air cylinder cannot be used. The stroke that the piston would then perform would be greater than the movement of the clutch pedal and this would cause a clutch failure. With this in mind, it has not been possible to utilize the advantages of a game-adjusting servo unit in gearboxes equipped with an interlocking device, but has been instructed to use manual adjustment of the clutch slats.

The present invention has for its object to eliminate the latter disadvantage and relates to an arrangement for clutch interlocking which can also be used together with servo units comprising automatic adjustment of the play between the clutch slats. For clutch actuation, a hydraulic circuit is arranged to transmit movements between an actuator and at least one actuating actuating means, the invention being mainly characterized in that a locking valve is connected in the hydraulic circuit comprising a non-return valve function which is controlled by a gear position sensor to allow flow of hydraulic media in the direction from the actuator to the actuating means and to block the flow of the hydraulic media in the opposite direction when the gearbox is not engaged in the gearbox.

Furthermore, the invention is characterized in that the gear position sensor consists of a piston slidably mounted in the interlock valve, the outer end of which is arranged abutting against the mantle surface on a control shaft slidably mounted in the gearbox and in engaging a recess formed on the control shaft when the gear is not engaged.

In an advantageous embodiment of the arrangement according to the invention, the operating means consists of a clutch pedal and the actuating means of a servo unit. The clutch pedal is then articulated to a hydraulic piston in a hydraulic cylinder, which is later connected via the interlock valve to a line connected to a hydropneumatic servo unit mounted in the vehicle, which is arranged to perform the actual disengagement work when activated.

The invention will be described in more detail below with reference to the latter embodiment, the description being carried out with reference to the accompanying figures, in which Figure 1 schematically shows a wiring diagram of an arrangement according to the invention for interlocking a vehicle coupling, and Figure 2 shows a cross section of an interlock valve included in this arrangement.

The arrangement according to Figure 1 is intended to be applied in a heavier vehicle, for example a truck, provided with a so-called split gearbox, which comprises a main gearbox (not shown) and an auxiliary gearbox 1 connected in series with each other. The main gearbox consists of a conventional vehicle gearbox with a plurality of gear positions, and the auxiliary gearbox 1 consists of a planetary gearbox with two possible gear positions. 'On previously known worn 111 * to tíllszntsvåixtelltitlnxx 1: msluterx lines' from a source of compressed air 2 in the vehicle. The auxiliary gearbox 1 is also connected to electrical wires from a gear selector 3, which comprises an electrical contact by means of which the gear selector 3 can be caused to assume either of two positions corresponding to the two gear positions of the gearbox 1. The gear selector 3 is connected to the vehicle's power supply source 6 via a clutch pedal contact 4 and a drive on the vehicle wheels disconnecting contact 5, which later in its initial position connects the clutch pedal contact 4 to the power supply source 6.

The coupling of the vehicle is operated by a coupling pedal 7 which is articulated to a piston 8 in a stationary hydraulic cylinder 9. This is in turn connected via a line 10 to a servo unit 11, which is arranged to perform the actual disengagement work. The servo unit 11 is mounted in the vehicle in a known manner and comprises a hydraulic piston 13 displaceable in a hydraulic cylinder 12, which is connected via a push rod 14 to a lever 15 intended for actuating the clutch. The said push rod 14 in the servo unit 11 also engages in a compressed air cylinder 16, in which a displaceably mounted compressed air piston 17 is pre-blown with the push rod 14 and via it can influence the lever 15 rotational movements for rupturing the coupling. The supply of compressed air to the compressed air cylinder 16 is regulated by a valve 18 controlled by the hydraulic oil pressure in the hydraulic oil line 10 so that the compressed air supply becomes proportional to the hydraulic oil pressure.

The servo unit 11 is designed in a known manner to automatically adjust the play of the clutch depending on the wear on the slats of the clutch, whereby the play becomes substantially constant. The above-mentioned hydraulic piston 13 and compressed air piston 17 therefore have a greater stroke than is otherwise justified for the coupling actuator.

The auxiliary gearbox 1 comprises an axially displaceable operating shaft 19, which in a known manner carries a shifting fork (not shown) for activating shifting loops (not shown) and for engaging a desired gear position. The control shaft 19 is then controlled by pneumatic piston-cylinder assemblies (not shown), which are controlled by electron magic valves (not shown), which in turn are controlled by the gear selector 3. Figure 1 shows only a part of this control shaft 19. , which at its outer end is provided with a radial recess 20 of limited axial extent.

A hydraulic valve 21 is connected in the hydraulic oil line 10 between the hydraulic cylinder 9 of the clutch pedal and the servo unit 11, the constructive design of which is described later. This valve 21 has two positions, a shut-off position 22, in which the valve acts as a non-return valve and only allows oil passage from the hydraulic cylinder 9 to the servo unit 11, and an open position 23, in which the valve 21 acts as an open connection allowing oil passage in both directions. The interlock valve 21 is provided with a shielding means 24, which is arranged to sense the gear position of the gearbox 1. In the case where no gear is engaged, the shielding means 24 abuts against and in the recess 20 of the operating shaft 19, while in other cases it bears against the operating surface 25 of the manhole shaft 19 on the side of said recess 20. The interlocking valve 21 then assumes an open position. 23 when a gear is engaged, while the valve 21: engages locking position 22 during the actual shifting process when no gear is engaged.

The interlock valve 21 is also connected via an electromagnetic valve 26 to the vehicle's compressed air source 2. Said valve 26 is regulated by means of the drive wheel disconnecting contact 5. When activating it, the valve 26 assumes an open position 27, whereby compressed air is supplied to the interlock valve 21, which then assumes its open position 23. At the same time, compressed air is also supplied to the control means 1 of the gearbox 1, which in a manner known per se sets the gearbox in a neutral position. When the valve 26 is not activated, the valve connection 28 from the compressed air source 2 is blocked and the valve connection 29 to the interlock valve 21 is then open to the surroundings so that deaeration is obtained.

The switch 5 for drive wheel disconnection is intended to be activated when it is desired to use a power take-off intended for an accessory unit or similar on the vehicle's gearbox while the vehicle is stationary, ie in conditions where no drive power transmission to the vehicle's drive wheel is etc. In such cases, the clutch interlock must be bypassed, and the auxiliary gearbox 1 must then be caused to assume a neutral position. This is achieved in a manner known per se by supplying compressed air via the valve 26 and a compressed air line 30 to the intended control means (not shown) in the auxiliary gearbox 1.

The constructive construction of the interlock valve 21 is shown in Figure 2. It can be seen that a valve housing 31 is formed with a connection chamber 32 for a line from the clutch pedal 7's hydraulic cylinder 9, a connection core 33 for a line from the valve 26 for drive wheel disconnection and a connection gun 34 for a line with connection to the servo unit 11. The valve housing 31 is formed with a cylindrical locking valve 35, which accommodates and forms a guide for a lower piston 36 and an upper piston 37. In the latter a upwardly open bottom hole is accommodated, in which a compression spring 38 is mounted . The spring 38 then abuts against the bottom plane 39 of the cylindrical hole 35 and presses the upper piston 37 into abutment against the upper side of the lower piston 36, which in turn is pressed into abutment against the operating shaft 19 and thereby acts as the sensing means 24 of the interlock valve 21.

Both pistons 36,37 are chamfered on their opposite sides, whereby an annular space 40 is formed between the pistons 36,37. This space 40 communicates via a channel 41 with the connection scanner 33. The jacket surfaces of the two pistons 36,37 are in the usual manner provided with seals 42 in the form of so-called O-rings, which seal the space 40 between the pistons 36,37. To enable evacuation of trapped air in the cylinder hole 35, a vent hole 43 is accommodated in the valve housing 31 which opens at the bottom plane 39 of the cylindrical hole.

A non-return valve 44 is also integrated in the valve housing 31. With respect to this, the valve housing 31 is formed with an upper shoulder-shaped cylindrical recess 50, in which the valve components are arranged. The outer part of the recess 50 is threaded and into it is mounted a mounting plug 51. In a bottom hole formed on the inside of the plug 51 is mounted a compression spring 46 which presses a valve ball 45 for abutment against a valve seat 47, which is later pressed into the recess 50 for abutment. against an approach. The valve seat 47 is designed in such a way that an inlet shaft 48 is formed in the non-return valve 44 which is connected to the hydraulic cylinder 9 via the connection shaft 32 and an outlet chamber 49 which is connected to the servo unit via the connection gun 34. At the bottom of the recess 50 is accommodated a concentric smaller heel 52 which eccentrically opens into the bottom plane 39 of the cylindrical hole 35. In said heel 52 is mounted an axially displaceable pressure pin 53, which with its lower end abuts against the upper piston 37 and with its upper end can cause the valve ball 45 to leave the valve seat 47. The pressure pin 53 is sealed with a seal S4 in the form of an O-ring.

A locking valve 21 designed as described will act as a non-return valve when the lower piston 36 of the valve 21 is in a lower position and thereby abuts against the bottom of the recess 20 of the control shaft 19, as shown in figure 2.

Said position is taken when no gear is engaged. Provided that the drive wheel disconnection valve 26 also assumes an inactivated position, the upper piston 37 must abut against the lower piston 36, and the ball 45 of the non-return valve 44 can thereby abut tightly against the valve seat 47.

Activation of the interlock valve 21 can take place in two different ways. One occurs when the gearbox 1 is engaged in a gear position and the other occurs when the drive wheel disconnection valve 26 is activated. In the first-mentioned case, the upper shaft shaft 19 will be displaced axially during the gear bearing, the lower piston 36 being actuated to assume an abutment with abutment against the non-recessed part 25 of the control shaft 19. This means that the upper piston 37 is pressed upwards and via the push pin 53 acts on the valve ball 45 to lean the valve seat 47, the valve 21 being able to allow the passage of hydraulic oil in both directions.

When activating the valve 21 according to the second alternative, compressed air is introduced into the space 40 between the calves 36,37. This causes the upper piston 37 to be pressed upwards and in an analogous manner actuates the pressure pin S3 and the valve ball 45.

A changeover of the auxiliary gearbox 1 carried out during the travel of the vehicle is usually started by setting a desired gear position with the gear selector 3. At the depressurized gearbox the carbon flange 7 closes; contact 4, and the gear unit 3 then receives current from the power supply source 6 via the drive wheel disconnection contact S. between the vehicle's engine and gearbox is performed.

In the auxiliary gearbox 1, a shift is carried out in a manner known per se with the aid of means intended for this purpose. In this case, the control shaft 19 of the gearbox is displaced, whereby the interlocking valve 21 with sensing against the bottom plane of the recess 20 will function as a non-return valve during the shifting process when no gear is engaged. If the actuation of the clutch pedal 7 ceases before the shifting process is fully completed, the interlock valve 21 will ensure that both the clutch and the clutch pedal 7 are kept in a disengaged position until its shifting position is changed.

Claims (5)

7907290-6 the process is completely completed, after which the adjacent means automatically return to their non-activated positions. The present invention is not limited to the described embodiment, but can be modified in alternative embodiments within the scope of the appended claims. PATENTKIRAV Arrangement for locking a vehicle clutch in a disengaged position for driving power transmission between an engine and a gearbox, wherein for clutch operation a hydraulic circuit is arranged to transmit movements between an actuator (7,9) and at least one clutch actuating actuating means (11 , 14), characterized in that in the hydraulic circuit is connected a locking valve (21) comprising a non-return valve function which is controlled by a gear position sensor (24,36) to allow flow of hydraulic medium in the direction from operating means (7,9 ) to actuating means (11,14) and to block the flow of hydruulineclin in the opposite direction at non-loaded gear in the gearbox. Arrangement according to claim 1, characterized in that the interlocking valve (21) comprises pressure-controlled controls (37, 53) by means of which the locking function of the interlocking valve (21) can be released when the gearbox is not engaged in the gearbox. Arrangement according to claim 2, characterized in that the gear position sensor (24) consists of a piston (36) slidably mounted in the interlock valve (21), the outer end of which is arranged abutting against the casing surface of a bearing slidably mounted in the gearbox (1). control shaft (19) and to engage in a recess (20) formed on the control shaft (19) when the gear is not engaged. Arrangement according to claim 3, characterized in that the gear position sensing piston (36) is actuated by a spring-loaded inner piston (37), which presses the piston (36) into abutment against the control shaft (19) and which, when pressure medium is supplied to a side space between the pistons (36,37) cancels the locking function of the interlock valve (21). Arrangement according to one of the preceding claims, wherein the operating means consists of a clutch pedal (7) and the actuating means of a servo unit (11), characterized in that the clutch pedal (7) is articulated to a hydraulic piston (8) in a hydraulic cylinder. (9) and that the hydraulic cylinder (9) is connected via the interlock valve (21) to a hydro-pneumatic servo unit (11), which is attached to the vehicle and arranged to perform the actual disconnection work when activated.