DE2230519A1 - CONTROL DEVICE FOR AN ADJUSTABLE PUMP - Google Patents

Description

May 16, 1972 Wd / Gü

Attachment to

Patent and

Utility model erhilf saninmeldung

ROBERT BOSCH GMBH, Stuttgart Control device for an adjustable pump

The invention relates to a control device for an adjustable Pump, the actuator of which is adjustable with the aid of at least one piston controlled by a control valve, which is controlled by a path input member can be actuated.

In such power-amplifying control devices, as they are frequently used, pressure medium is supplied from the control valve controlled to the actuating piston of the actuator. The path input link

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Robert Bosch GmbH Wd / Gü R. ⁹ *

Stuttgart

can take effect directly or indirectly on the control slide. Such control devices make it possible to large To exert forces, but have the disadvantage that they do not position the actuator very precisely.

It is an object of the invention to provide a control device of the type mentioned at the outset which works very precisely, d. H. adjusts the position of the actuator very precisely.

This is achieved according to the invention in that the piston is connected to the control slide via a rigid transmission member and that the path input member is articulated on the transmission member in such a way that it is in two unequal length sections divided, this articulation point closer to the articulation point of the piston on the transmission link than at the articulation point of the control spool is on the transmission link.

This means that transmission ratios can be achieved on the transmission element, the overlap failure on the control spool in the Decrease return.

It is particularly useful if a zero position feedback is provided for the actuator of the pump, which directly on the transmission element acts. This means that, for example, the pump opens automatically after releasing the V / eg input element Flow rate set to zero.

A particularly simple and rough control device results when the path input member is firmly connected to a shaft provided with an adjusting lever, which on both sides in is mounted in a housing of the control device, and v / hen the shaft passed through a recess in the transmission member is.

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Robert Bosch GmbH Wd / Gü R. ⁹ * *

Stuttgart

An embodiment of the invention is shown in the drawing. This shows in

Fig. 1 shows a first embodiment of the control device in a schematic representation;

Fig. 2 is a route diagram;

3 shows a longitudinal section through the control device according to FIG the embodiment of FIG. 1;

Fig. 4- shows a cross section along IV ... IV according to Fig. 3;

5 shows a second exemplary embodiment of the control device in a schematic representation;

6 is a V / e diagram;

7 shows a longitudinal section through the control device according to FIG the embodiment of FIG. 6;

Fig. 8 shows a cross section along VIII ... VIII according to the embodiment of Fig. 7;

9 shows a third exemplary embodiment in a schematic representation;

10 and 10a a fourth embodiment in a schematic representation.

In the Ausfülirungsbeispiel according to Fig. 1, 11 is an 'adjustable Pump referred to in a rotor 12 several radially accommodates arranged piston. Their ends protruding from the rotor lie on an actuator designed as a cam ring 14

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Robert Bosch GMBH . V / d / Gü R. 9 \

Stuttgart

on, which can be displaced between guides 15 and 16 relative to the rotor is arranged. To adjust it, two diametrically opposed pistons 17 act on the cam ring and 18 a. The piston 17 is guided in a tightly sliding manner in a bore which has a pressure chamber 19 '. In which one on the Piston 17 acting spring 20 is arranged. The piston 18 is guided in a tightly sliding manner in a bore 21 which forms a pressure space 21 ', in which a spring 22 acting on the piston 18 is arranged.

A line 23 leads from the pressure chamber 19 'of the bore 19 to a Directional control valve 24, in the slide bore 25 of which a control slide 26 is guided so as to slide tightly. From an annular groove 27 of the Slide bore 25 leads a line 28 to the pressure chamber 21 'of the Bore 21. A line 30 leads from an annular groove 29 of the slide bore 25 to a container 31. The annular grooves 27 and 29 , lie to the left and right of the point at which the line 23 ends into the slide bore 25 ″ · A delivery line 32 is connected to the pump 11, which leads to a consumer and to Many marriage also the line 28 is connected.

Two annular grooves 35 and 36 are formed on the control slide 26, of which the annular groove 35 with the annular groove 27 of the control slide bore, the annular groove 36 with the annular groove 29 of the control slide bore cooperates. A rod 37 is articulated on the control slide 26, the free end of which is connected to a transmission member Lever 38 is hinged (point B). The other end of the lever 38 protrudes into a slot 39 of a rod 40 which is on Piston 17 is attached (point A). Approximately in the middle of the rod there is a recess 41 in the form of an elongated hole. Between the pivot point A of the lever 38 on the rod 40 and the elongated hole 41, a bolt 42 is arranged on the lever 38 (point C).

An adjusting shaft 43 is rotatable in the housing of the control device arranged, with the non-rotatable the path input member 44 in

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Form of a z \ tfeiarmigen lever is firmly arranged. At the end of a lever arm is a fork 45, in which the bolt 4-2 of the lever 38 engages. At the end of the second lever arm a rounding 46 is formed on which two springs 47 are supported, which act in opposite directions on the rounding 46. A stop fixed to the housing is located between the two springs 49 arranged, which limits the movement of the spring 47 in the zero position. The spring 47 has a greater biasing force than the spring 48. An adjusting lever 50 is fixedly arranged on the adjusting shaft 43. The central axes of the two compression springs 47, 48 form a right angle with the axes of the control slide and the pistons 17 »38.

The same parts as in FIG. 1 are shown in FIGS. 3 and 4 denoted by the same numbers. Figures 3 and 4 show a practical embodiment, as shown in Figure 1 schematically is shown. Minor constructional differences are not discussed further here.

The control device according to this exemplary embodiment works as follows: If the adjustment lever 50 is out of its neutral position Swiveled counterclockwise - as shown - so also rotates the adjusting shaft 43, and that on it Angular levers 44 arranged in a non-rotatable manner also performs a pivoting movement. As a fixed point of the adjustment rod is consider point A, d. H. the articulated connection of the lever 38 with the rod 40, namely because the Piston 17 cannot move because control slide 26 is in its neutral position at the start of the steering wheel. As a result ■ of this, the lever 38 is now about point A in a clockwise direction pivoted, whereby the rod 37 the control slide 26 to the right, d. H. away from the spring 48, shifts. Through this The control slide can now move out of the delivery line 32 and the line 28 connected to it and via the annular groove 35 on the control slide pressure medium via the line 23 into the

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Robert Bosch GmbH Wd / Gü R. 9 1

Stuttgart

Flow pressure chamber 19 '. In the pressure chamber 21 'there is also delivery pressure, since this is always connected to the delivery line J2. However, since the area of the piston 17 is significantly larger than that of the piston 18, the force on the piston 17 is significantly greater than that on the piston 18, so that the stroke ring 14 is shifted to the right, ie in the direction of the small piston 18. The delivery rate of the pump will now increase if it was previously in the neutral position. This can be seen in the path diagram according to FIG. 2. Point A is the fixed point, point C has moved to C, point B to B ¹ . Since the lever 38 is divided into unequal lengths by the point C, in such a way that the point C, ie the bolt 42 is closer to the point A, the path BB ^{1 is} significantly greater than the path CC. This means that the control slide 26 covers a greater distance than point C and thus the bolt 42. This is intended because it contributes to the accuracy of the control if the control slide covers longer distances than articulation points in the linkage. This is due to the fact that the control slide always has to cover a certain distance until its control edges establish connections between the lines. The greater travel on the control slide ensures that inaccuracies between the control slide edges and line connections have little influence due to the large travel on the control slide.

As a result of the movement of the piston 17, point A has moved to A ¹ . The fixed point is point C, since the linkage is not actuated now. As a result of the movement of the piston 17, the control slide is now shifted back from point B 'around fixed point C to point B, that is to say back to its original neutral position. The mentioned line connections are now interrupted again. It can be seen from this that the lever 38 also has a return function. The spring 47 was also pretensioned by the pivoting movement of the adjusting lever 50. If one now leaves the adjusting lever 50, for example

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go, then the previously tensioned spring 47 can move the angle lever again pivot back against the force of the spring 48, and until the spring has reached the stop 49. Through this the pump is automatically reset to zero flow rate.

The adjusting lever is now adjusted clockwise and thereby If the angle lever 44 is rotated clockwise, then the lever J8 is counterclockwise at the start of control around the fixed point A pivoted.- This causes the control slide 26 of the rod 37 to the left, d. H. shifted in the direction of the spring 48 out. This has the consequence that the pressure chamber 19 'on the Line 23 and the annular groove 29 to the container 31 is relieved, d. H. Pressure medium can flow out of the pressure chamber 19 'to the container. However, since there is still high pressure in the pressure chamber 21, the piston 18 now pushes the cam ring 14 to the left. Through this the delivery rate of the pump is reduced if the cam ring was previously approximately in the position shown in FIG. Your delivery rate would, however, be increased if the cam ring was in the middle position at the beginning of the pivoting movement of the adjusting lever 50 were. It can be seen from this that the cam ring 14 moves to the left is when the adjusting lever is pivoted clockwise will, and vice versa.

By moving the cam ring 14, the piston 17 is also has been postponed. His rod 40 now pivots the lever 38 around the current fixed point C clockwise, whereby the control slide 26 is moved back into its neutral position. Even from this, the return function of the lever 38 can be seen again. If the spring 47 was previously pretensioned, it is now the spring 'Ί8. If you let go of the adjusting lever 50, the preloaded one pushes Spring 48 the rounding 46 in its middle position, xby which the pump is also set to the full delivery rate, as described above. From the diagram according to FIG. 2 it can be seen that the transmission ratio A = BC / AO 1

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Robert Bosch GMBH . Wd / Gü R.! 9 '

Stuttgart

and the ratio BC / AB-C1.

The embodiment according to FIG. 5 differs from that the above essentially in that the springs 47 now run parallel to the axial direction of the pistons 17, 18, and that the path input member is no longer designed as an angle lever. Otherwise are the same parts as in the execution leg game denoted by the same numerals according to FIG. 1.

The adjusting lever 50 is in turn locked in rotation with the shaft 43 ' connected, but this time has only one bearing point in the housing of the adjusting device, as shown in FIGS. 7 and 8 is shown which, a practical embodiment according to Fig. 5 show. The adjusting shaft 43 'cannot be rotated a one-armed lever designed as a path input member arranged, which has a fork 54 at its free end, in which a bolt 55 engages. This in turn represents point C. The bolt 55 is at End.e as a transmission link trained one-armed lever 56 arranged. Some Above the bolt 55 there is a second bolt on the lever 56 arranged, which protrudes into a slot 57 of the rod 40, which is attached to the piston 17. The bolt 58 corresponds again the point A. At the end of the lever 56 opposite the bolt 55, a rounding 59 is formed, on which in turn the both springs 47 and 48 are in contact. Slightly below the curve a bolt 60 is arranged on the lever 56, on which a Rod 61 is articulated, which is connected to the control slide 26. The control slide 26 is designed in exactly the same way as in the previous exemplary embodiment, but the connections of lines 28 and 30 are interchanged. The one with the pump delivery line connected line 28 now opens at the annular groove 29? while line 30 to container 31 in the annular groove 27 leads.

If the adjusting lever 50 is out of its vertical central position to the left - v / ie shown in the drawing - pivoted,

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d. H. counterclockwise, then the lever 53 is also pivoted counterclockwise. The point A forms turn the current fixed point in the linkage, so that the Lever 56 is now pivoted about point A also counterclockwise. As a result, the spool becomes moved to the left, whereupon connection is established from the line 28 to the pressure chamber 19 '♦ This has the consequence that the Lifting ring 14 is displaced by the piston 17 to the right. This process is exactly the same as described above. By the Pivoting the lever 56, the rounding 59 was also shifted to the left, whereby it pretensions the spring 47. In addition, was by the movement of the piston 17 via the lever 56 also the Control slide brought back to its middle position. It can be seen from this that the lever in turn has a feedback function having. If you let go of the adjusting lever 50, then pushes the spring 47 the rounding 59 back in its central position. The control slide is then moved to the right, as the Point A in turn forms the current fixed point. This has the consequence that now pressure medium from the pressure chamber 19 'to the container can flow off, whereupon the piston 18, at which there is always high pressure, brings the cam ring 14 into its central position. It can be seen from this that there is again a zero position feedback.

The adjusting lever 50 moves to the right from its central position pivoted, the pressure chamber 19 'to the container is relieved, and the piston 18 now moves the cam ring 14 to the left.

From the diagram according to FIG. 6, the paths at the individual points A, B, C can again be seen. It can be seen from this that the path of the control slide BB ^{1 is again} greater than the paths AA ¹ or C C. However, the ratio BG / A3 is now> 1, the transmission ratio again BC / AO-1.

A practical embodiment is shown in FIGS. 7 and 8 shown. There is no minor constructional differences

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received, since these can be recognized without further information.

As a simplification of the embodiment according to the figures up to 4 there is the liullage return which is part of the lever 56.

The embodiment according to FIG. 9 is constructed similarly to that according to FIG. The same parts as there or in the exemplary embodiment according to Fig. 1 are again denoted by the same numerals. The similarity to the execution example after the Fig. 5 is that the transmission member directly is connected to the ITullage feedback. In the exemplary embodiment according to FIG. 5, the ITullage return was above of the control slide 26 ', it is now below the control slide, which is otherwise designed in the same way as in the embodiment according to Fig. 5

This is in turn designed as a lever 62 transmission member at its upper end at point 3 with the control slide 26 ' articulated. The adjusting shaft 4J 'mounted in the housing is in turn firmly connected to the one-armed lever 53. The bolt 55 of the lever 62 engages in its fork 54. A little above of the bolt 55, the bolt 58 is attached to the lever 62 and engages in the slot 57 on the rod 40 of the piston 17 The bolt 58 again corresponds to the point A, the bolt 55 to the point C. In contrast to the above embodiment the lever 62 continues beyond the bolt 58 and ends in a rounding 65 · Against this lie the springs 47, 48 of the ITullage return. On the opposite At the end of the lever 62 there is a bolt 62 '(point B) which ends via the rod 61 with the control slide 26'. It can be clearly seen from this that the exemplary embodiments 5 and 9 are largely similar. Correct in their function they completely agree, so that this is not discussed further.

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Robert Bosch GmbH 'Wd / Gü R. 9 *

Stuttgart

In the embodiment according to FIG. 10, the transmission element rests directly on the control slide. It bears the designation 70 and is in turn designed as a lever which has an approximately circular curve 71 at one end. This rests directly on the control slide, which is designated by 72. Approximately in the middle of the lever 70 is a bolt 73 ₅ cLer protrudes into the slot 57 of the rod 40 of the piston 17 (point A). A bolt 75, which is articulated to a two-armed lever 76, is fixedly arranged on the lever 70 below the bolt 73. The two-armed lever 76 is firmly seated on the adjusting shaft 43, which in turn is mounted on both sides in the housing of the control device. The adjusting lever 50 is firmly connected to the adjusting shaft. The lever 70 extends beyond the bolt 75 and ends in a rounded portion 77 on which the springs 47, 48 rest. These in turn represent the known zero position feedback. When the adjusting lever 50 is pivoted, the curve 71 shifts eccentrically with respect to the adjusting shaft 43, as shown in FIG. 10a. The control slide 72 is therefore not connected to the lever 70 in an articulated manner with the aid of a rod, but is pressed against the cam 71 in a force-locking manner by a spring 78. The adjusting shaft 43 corresponds to point B, the articulation point of the rod 74 on the lever 70 to point A, the connection of the lever 70 with the "lever 76" corresponds to point C and the center of the circular body 77 to point D.

The mode of operation of this exemplary embodiment corresponds exactly to that of the exemplary embodiments according to FIGS. 5 and 9? so that did not go into further detail.

In the exemplary embodiments according to FIGS. 3, 4, 7, 8, 11 and 12, details such as spring plates, leakage oil bores, sealing rings and the like are not identified in detail because their Arrangement for the designer are a matter of course.

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Claims (9)

Robert Bosch GmbH Vd / Gü H. 9 * Stuttgart claims 1.) Control device for an adjustable pump, the actuator of which is adjustable with the aid of at least one piston controlled by a control valve, which can be actuated by a path input member, characterized in that the piston (17) via a rigid transmission member (33, ^l ) 6, 62,? O) is connected to the control slide (25, 26 ', 72) and that the path input member (44, 53 »76) is articulated on the transmission member (38, 56, 62, 70) in such a way that it divides this into two unequal length sections, this articulation point (C) being closer to the articulation point (A) of the piston on the transmission link than at the articulation point (B) of the control slide on the transmission link. 2. Control device according to claim 1, characterized in that a hull position feedback for the actuator (14) of the pump (12) (47, 48) is provided, which directly refers to the Transfer member acts. 3. Control device according to claim 2, characterized in that a NuIlage feedback for the actuator of the pump is provided, which acts on the transmission member via the path input member (44). - 13 309882/0187 Robert Bosch GmbH Wd / Gü RL 9 ¹ Stuttgart 4. Control device according to claim 2 and 3 j, characterized in that that the zero position return two opposing springs (47> 4-8) that act on the transmission element or the path input element. 5. Control device according to claim 1 to 4, characterized in that that the path input member (44-, 53 j 76) is firmly connected to a shaft (43) provided with an adjusting lever (50) is, which is mounted on both sides in a housing of the actuating device, and that the shaft through a recess (41) of the transmission member (38) is passed through. 6. Control device according to one of claims 1 to 5 »characterized in that the path input member (44) is designed as an angle lever, at one end of which there is a fork (45) into which a pin arranged on the transmission member (38) is located (42) protrudes, and that on the other 'end of the
two-armed lever, the zero position feedback acts. 7. Control device according to claim 1, characterized in that a cam (71) is arranged on the transmission member (70) is on which the control slide (72) rests directly and that the curve through the path input member (50, 76) is eccentric movable with respect to the shaft (43) ds "C. - 14 309882/0187 Robert Bosch GmbH Wd / Gü R. 9 1 3 Stuttgart 8. Control device according to one of claims 1 to 7, characterized • marked that the control device from the delivery pressure of the The pump itself is acted upon so that its actuator (14) consists of a displaceable cam ring on which to each other two pistons (17, 18) act at diametrically opposite points. 9. Control device according to one of claims 1 to 8, characterized in that the control slide as a two-edge slide is formed and that one of the pistons (18) always depends on the delivery pressure the pump is pressurized. 309882/0187 Blank page