JP3523333B2 - Electromagnetically operable pressure control valve - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an electromagnetically actuatable pressure control valve, in particular for an automatic transmission of a motor vehicle, which has a distributor casing with a pressure medium passage and a control groove. A control piston is movably arranged therein, which is directly actuable via a magnetic armature and has at least two piston sections which cooperate closely with the distributor casing. And during the division,
It is of the type in which the pressure medium passage for loading the consumer at a controlled pressure is open.

[0002]

2. Description of the Prior Art A pressure control valve of this kind is known from DE 32 32 229 A1. The pressure control valve has a control piston located in the distributor casing, which is guided in the longitudinal bore via two piston sections. Distributor casings and control pistons of this kind are expensive to manufacture. The reason is that, for a given construction space, the achievable magnet force allows only a small diameter for the control piston within a given pressure control range. Due to the magnetic forces limited by the structural space, relatively low control pressures and low pressure medium flows are only permitted. The ring passage with the hole for receiving the control piston and the corresponding control edge in the distributor casing is very difficult to machine for small diameters and requires a very thin rotary tool. In order to eliminate this drawback, German utility model No. 83
No. 22570 is known, in which a small-diameter pin, which is mounted on the control piston in a sliding manner and which is loaded by a control pressure, can act. However, this additionally requires an expensive part, which is expensive to manufacture and at the same time requires a large structural length of the pressure controller. Furthermore, due to the costly pressure medium guide, an additional leak passage is created.

Further, German Patent Application Publication No. 3818
No. 109 discloses a pressure control valve on which the control piston has at least three dense piston sections, of which the first two sections have the same diameter and
The diameter of the section is small. A controlled pressure is then built up between the two piston sections of equal diameter. This controlled outlet pressure is returned to the intermediate chamber between two piston sections of different diameter via a return guide passage or an external passage formed as a passage on the outer circumference of the distributor casing.
This allows for higher pressure control. However, this results in a relatively long distributor casing and control piston. More specialized return passages are required. The costly distributor casing requires a large number of pressure medium passages and connections. Furthermore, in this pressure control valve, the risk of contamination of the movable part chamber is extremely high. This is because the armature chamber must be sealed against the high return pressure by a small diameter piston section.

[0004]

The object of the present invention is to eliminate the abovementioned drawbacks.

[0005]

SUMMARY OF THE INVENTION The present invention was able to solve the above problem by virtue of the two piston sections having different diameters.

[0006]

The electromagnetically actuable pressure control valve according to the invention with the features of claim 1 achieves both high control pressure and high flow-through with a low production engineering outlay. This has the advantage that the control piston can work directly with the magnetic armature without pre-control.
Further, the pressure control valve of the present invention has a small structural length and can be manufactured with a small number of structural members. The control piston is simple in construction, so that it is easy to manufacture and is insensitive to contamination.

When the magnetic mover or its operating part is pressed against the control piston by the action of the spring member, the radial force of the control piston cannot be transmitted to the magnetic mover, so that Very convenient for bearings.

By arranging the piston sections with the larger diameter spatially corresponding to the magnetic armature, a pressure with a drooping or increasing characteristic (control pressure vs. excitation current) is achieved in a simple manner. A control valve can be made and can be driven by structurally identical magnet parts.

Other advantages and advantageous configurations of the present invention are:
Claims 2 and below and in the following description.

[0010]

Two embodiments of the present invention will be described in detail with reference to the following description and drawings.

FIG. 1 shows a pressure control valve having a substantially cup-shaped magnet jacket 10. A hollow cylindrical core 12 projects from the bottom portion 11 into the magnet jacket 10. The core 12 includes a magnetic coil 13 and a coil body 14.
Surrounded by and. The core 12 is closed in the region of the bottom 11 by means of an adjusting screw 15, which screw 1
5 is penetrated by a longitudinal hole 16. The longitudinal bore 16 itself is closed by a squeezed ball 17. A bearing pin 18 of a magnet shaft 19 is slidably guided in a longitudinal hole 16 of the adjusting screw 15. This magnet shaft 19
Extends coaxially with respect to the core 12 and is fixedly coupled to the disk-shaped magnetic armature 20. The magnetic armature 20 includes a magnet jacket 1 in front of the free end surface of the magnetic coil 13.
It is located in the mover chamber 21 arranged inward of 0.
The magnetic armature 20 is loaded on its side facing the core 12 by a compression spring 22, and the other end of the compression spring 22 abuts on the adjusting screw 15. The free end 23 of the magnet shaft 19 passes through the magnetic armature 20 and a disk-shaped diaphragm spring 24 that is immovably coupled to the magnet shaft 19 and the magnetic armature 20. The diaphragm spring 24 is stretched around the outer peripheral portion thereof between the step portion 25 of the magnet outer jacket 10 and the connecting member 26 of the distributor casing 27. At this time, the magnet outer jacket 10 and the connecting member 26 are bent by edge bending. They are fixedly connected to each other.

The distributor casing 27 is penetrated by stepped longitudinal holes 29, 30 which, starting from its connecting member 26, have a larger diameter hole section 29.
Have migrated to smaller diameter hole sections 30. The free end of the small diameter hole section 30 is
7 is closed by a perforated plate 31 which is fixedly connected to 7, through which holes 29, 30 are connected to the container (return part), the connection being designated by the symbol T. ing. The small-diameter hole section 30 has a first control ring groove 33, which is connected to the pressure medium source via a lateral hole 34 through the distributor casing 27, the connection of which is designated by the reference numeral. It is represented by P _ZU .
In the area of the large diameter hole section 29, the second control ring groove 3
5, the ring groove 35 is connected to a container or return via a transverse hole 36 through the distributor casing 27, which connection is designated by the symbol T. The large diameter hole section 29 has a first control ring groove 33.
And a second control ring groove 35 are penetrated by a third lateral hole 37 which is connected to the consumer machine, the connection of which is designated P _r .

A control piston 39 is guided in the bores 29, 30 and has its two piston sections 40, 4 sealed.
1 are connected to each other by a thinner piston neck. The piston section 40 with the small diameter d ₁ is closely and slidably guided in the small diameter bore section 30.
On the other hand, a piston section 41 with a large diameter d ₂ is guided in the bore section 29. The free end face of the piston section 41 has a cylindrical addend 42, which abuts the free end 23 of the magnet shaft 19 which acts as an actuating member.

Since the magnetic coil 13 of the pressure control valve is not energized at the switching position shown in the figure, the magnetic mover 20 to the magnet shaft 19 are actuated by the spring 22 to control the piston 39.
The small diameter piston section 40 bears against a perforated plate 31 which serves as a stop. At this switching position, the second control ring groove 35 is
Is covered by a large diameter piston section 41,
Therefore, the lateral hole 3 connected to the container or the return T
6 is closed on one side. The transition between the small diameter piston section 40 and the piston neck 39, which acts as a first control edge 45, is then the first control ring groove 3
It is located in the central region of 3. Therefore, the connection, which is almost unsqueezed, extends from the lateral bore 34 connected to the pressure medium source (PZU) to the first control ring groove 34 and between the piston neck 39 and the longitudinal bore 29, 30. The ring chamber 46 leads to a third lateral hole 37 connected to the consumer machine (Pr). Due to the increased pressure in the ring chamber 46, the control piston 39 is directed to the right against the action of the spring 22 due to the different acting diameters (d1, d2) of the piston sections 40 and 41. Power acts.
When the force due to the increased pressure in the pressure chamber 46 exceeds the value defined by the bias of the adjustable spring 22, the control piston 39 moves to the right against the action of the spring 22. The flow of pressure medium from the pressure medium source PZU through the transverse bore 34, the ring chamber 46 and the third transverse bore 37 to the consumer is then restricted by the small ring gap at the first control edge 45. Consumer machine (P
If the controlled pressure in the ring chamber 46 against r) rises further, it is between the piston neck 39 and the piston section 41.
The second control edge 47 at the transition of
The area of the groove 45 is reached. By this, phosphorus
Passing through the chamber 46, the second control ring groove 35 and the lateral hole 3
Through the return part to the container T (Po)
Additional connections are formed at the second control edge 47.
A controlled pressure Pr can thus be built up in the consumer, which pressure Pr is defined by a throttled inflow at the first control edge 45 and a throttled outflow at the second control edge 47. As the pressure in the ring chamber 46 increases further due to changes in the inflow at the consumer, the control piston 39 moves further to the right, which further reduces the feed cross-sectional area at the first control edge 45, while the second The outflow cross-sectional area at the control edge 47 is increased.
If the pressure rise is too great, this movement is continued until the first control edge 45 completely closes the first control ring groove 33, so that the consumer moves to the ring chamber 46.
There will only be a connection to the return T, which passes through the second control edge 47 which is opened via. This causes the pressure in the ring chamber 46 to drop, causing the control piston 39 to move back to the left and establish a balance.

In order to change the control pressure P _r in the consumer, that is to say in the case of the embodiment shown here, to reduce P _r , the magnetic coil 13 is energized and the magnetic armature 20 is activated. The coil 13 is pressed against the action of the compression spring 22. The control piston 39 follows to the right on the basis of the pressure built up in the ring chamber 46 and on the basis of the different working diameters of the piston sections 40 and 41 of this movement, so that the throttling action at the first control edge 45 occurs. , It will already occur in case of small control pressure. As the strength of the current in the magnetic coil 13 increases, the magnetic mover 20 is further pulled toward the magnetic coil 13. Therefore, a drooping type control pressure-exciting current characteristic can be formed for the pressure control valve.

In the pressure control valve described here, the controlled pressure does not return to the free end face of the control piston 39 as it does in conventional pressure control valves of this kind. Rather, the return device is an effective surface in the ring chamber 46, which arises from the different diameters (d ₁ , d ₂ ) of the two piston sections 40 and 41. This allows high control pressures and relatively weak magnetic strength
A large limiting piston diameter can be realized. This is because the action of the spring 22 or of the magnetic force in the opposite direction only depends on the difference in cross-sectional area of the two piston sections 40 and 41 on the basis of the control pressure.

This makes it possible to dispense with external costly returns over the special positions in the mounting position, the distributor casing or the control piston.

By spatially arranging the second control edge 35 against the armature chamber 21, due to the slight pressure difference during operation, from the armature chamber 21 to or to the armature chamber 21 in the piston section 41. , Only a slight leakage flow will occur. This also minimizes or prevents jetting of ferromagnetic contaminant particles into the armature chamber 21. The sealing against the second control ring groove 35 of the movable chamber 21 or the outflow into the container T is performed by the piston section 41 (gap seal). Leakage oil generated from the first control ring groove 33 through the piston section 40 to the free end surface of the control piston 39 is guided via the perforated disc 31 to the return section or container T. Due to the lateral force-free cooperation of the control piston 39 and the magnet shaft 19, the bearing of the magnetic armature 20 can be constructed relatively simply. The magnetic armature 20 and the magnet shaft 19 are in this case supported on the one hand in the adjusting screw 15 by means of bearing pins 18 and, on the other hand, guided by a diaphragm spring 24. At that time, the magnetic mover 20 and the magnetic coil 13 to the core 1
Lateral forces occurring in the air gap between the two are received by this diaphragm spring 24.

FIG. 2 shows a variation in the case of using the above-mentioned pressure controller. In this case, the holes 29 and 3 are formed.
The leakage oil cannot be guided from 0 to the free end surface of the distributor casing 27. In this case, the holes 29, 30 of the distributor casing 27 are closed by closed plates rather than by perforated plates. In order to drain the leakage oil flowing along the piston section 40, the control piston 39 has a blind hole 49 extending longitudinally starting from the free end face of the piston section 40A.
9 opens into a lateral hole 50 which extends in the region of the second control ring groove 35 and penetrates the piston section 41A. As a result, the free end face of the piston section 40A is
And the second control ring groove 35 via the lateral hole 50, and thus to the return part or the container T.

A second embodiment of the pressure control valve is shown in FIG. 3, in which case the control piston and the distributor casing have a different configuration, so that the pressure with the increasing characteristic of control pressure-excitation current is increased. A control valve is possible. In that case, this second
For the pressure control valve, a magnet section similar to that described in the embodiment of FIG. 1 is used.

The distributor casing 27B is likewise penetrated by longitudinal bores 29B, 30B, in which case the bore section 29B opening into the armature chamber 21B has the smaller diameter. Large diameter hole section 30B
Is closed in the region of the free end face of the distributor casing 27B by a plate 31B which is closed and tightly connected to the distributor casing 27B. Longitudinal hole 29
B and 30B likewise have two control ring grooves, the first control ring groove 33B being located in the region of the larger diameter hole section 30B and the second control ring groove 35B being the smaller diameter hole section 29B. Located in the area of. The second control ring groove 35B is connected to the pressure medium source via the inclined hole 52, and the connecting portion is represented by P _ZU . Consumer machine P
_r is a large diameter hole section 30 between the hole section 29B and the first control ring groove 33B via the second inclined hole 53.
Connected to B. Due to the arrangement of the inclined holes 52 to 53 in the distributor casing 27B, a space for the pressure medium connection and the consumer contact in the built-in chamber, similar to that provided for the pressure control valve of FIG. 1 or 2. Placement is guaranteed. That is, this pressure control valve with an increasing characteristic is suitable for a connection profile similar to the previously described pressure control valve with a drooping characteristic. Between the second control ring groove 35B and the armature chamber 21B, the hole section 29B is penetrated by a lateral hole 36B passing through the distributor casing 27B, which hole 36B leads to the return or the container T (P _o ). It is connected.

The control piston 39B has a longitudinal bore 30.
3 piston sections 5 closely cooperating with B, 29B
It has 5, 56, 57. In that case the first of the large diameter
The piston section 55 is located in the area of the first control ring groove 33B, while the second piston section 56 is located in the area of the second control ring groove 35B. The third piston section 57 is located in the hole section 29B between the lateral hole 36B and the armature chamber 21B and serves as a seal for the longitudinal holes 29B, 30B of the armature chamber 21B.

The control piston 39B is the first piston section 5
In the region of 5, there is a cylindrical recess 58 starting from its free end face, the bottom of which bears a spring 59, the other end of which rests against the plate 31B. A blind hole 60 extends longitudinally from the bottom of this recess, which blind hole 60 is connected to the second piston section 56 and the third piston section 56.
It is pierced with the piston section 57 by a transverse bore 62 extending through the piston neck 61. Hollow 5
8 has a lateral bore 63 which penetrates the piston section 55 in the region of the first control ring groove 33B.

Since the above-mentioned pressure control valve is shown in the same non-energized state, the spring 22 (not shown) of the magnet portion presses the magnet shaft 19 or the magnetic armature 20 against the control piston 39B. There is. In this example, the distributor casing 27B to the connecting member 26B are the magnetic movers 20.
Serves as a stopper for. The control piston 39B is then pressed by the action of the spring 59 against the magnetic armature 20 or the magnet shaft 19 which abuts the distributor casing. The spring stiffness of the spring 59 is then less than the spring stiffness of the spring 22 of the magnet part 22, not shown.

In the non-energized magnetic coil, the magnetic armature 20--as in the previous case--is the distributor casing 2.
7B, the control piston 39B is pressed against the magnet shaft 19 by the action of a spring 59. In this switching position the first piston section 5
5 covers the first control ring groove 33B, so that the ring groove 33B has a lateral bore 63 and a control piston 39B.
It is connected to the return or container T (P _o ) via a blind hole therein, a lateral bore 62, a ring chamber 65 between the piston neck 61 and the bore section 29B, and a lateral bore 36B. . At that time, the second piston section 60 is connected to the second control ring groove 35B.
Is located in the area of the
5 is sealed. Second piston section 5 at the same time
6 through the narrow throttle gap at the control edge 66 on the left side of the pressure medium connecting the feed medium P _ZU to the inclined hole 52.
And through the second control ring groove 35B to the ring chamber 67 between the two piston sections 55 and 56. Therefore, the strongly restricted pressure medium flow is generated in the second piston section 56.
From the pressure medium source P _ZU to the consumer P _r through the control edge 66 on the left side of. When the pressure in the ring chamber 67 exceeds the value defined by the biasing of the spring 59, the control piston 39B causes the first piston section 55 to move.
And the different working surfaces of the second piston section 56,
It moves to the left against the action of the spring 59. The throttle gap at the control edge 68 of the first piston section 55 is then opened, while the throttle gap at the control edge 66 of the second piston section 65 is reduced or closed. This causes the ring chamber 67 to pass through the control edge 68 of the first piston section 55 and pass through the first control ring groove 3
The pressure is released against 3B. This ring groove 33B is then again connected via the lateral bore 63, the blind bore 60 in the control piston and the subsequent lateral bore 36B-as already explained-to the return or container T. Become. As a result, the pressure in the ring chamber 67 or the controlled pressure P _r for the consumer is reduced again and a balanced state is formed. This equilibrium condition applies to piston sections 55 to 5
6 caused by the diaphragm cross-sections at both control edges 68-66. As the pressure in the ring chamber 67 rises further under the influence of the consumer, the control piston 39B opposes the action of the spring 39, until the throttle gap at the control edge 66 of the control piston 39B is completely closed.
It can be slid further to the left. This allows the consumer to be connected only to the return part via the ring chamber 67 and the further enlarged throttle gap at the control edge 68 of the first piston section 55, whereby the interior of the ring chamber 67 is closed. The pressure, or the pressure built into the consumer, will decrease.

When an electric current is applied to the magnetic coil of the magnet portion in order to increase the control pressure of the pressure control valve, the magnetic armature 20 and the magnet shaft 19 are pulled against the action of the spring 22 (not shown). become. By this, at the same time,
The control piston 39B is slid further to the right under the action of the spring 59 and comes into contact with the magnet shaft 19. This increases the throttle gap at the left control edge 66 of the second piston section 56, while reducing or closing the throttle gap at the control edge 68 of the first piston section 55. Therefore, in the ring chamber 67, a control pressure higher than (P _r ) which is also found in the consumer machine is formed.

The pressure control valve shown in FIG. 3 has-as already mentioned-an increasing control pressure-exciting current characteristic.

Instead of loading the control piston 39B by a force based on the action of the spring 59, it is also possible to choose a pressure loading device. In this case, the pressure chamber is connected to a (constant) pressure source between the control piston 39B and the plate 31B, for example to the supply of the pressure control valve. It is also possible to combine the load of the control piston 39B with a force based on the action of (hydraulic) pressure and the action of a spring.

In order to simplify the somewhat expensive pressure medium supply from the pressure medium source and the consumer via the inclined holes 53 and 52 to the longitudinal holes 29B, 30B, the control ring groove or longitudinal hole is As shown in FIG. 1, it is loaded through the lateral holes. In that case, however, the position of the pressure medium supply different from that of FIGS. 1 and 2 is formed by the pressure medium source and the pressure medium discharge to the consumer in the installed state.

It is also possible to realize the increased control pressure-excitation current characteristic in a simple manner by means of the magnet part acting in the opposite direction (opposite force direction). But in that case,
It would abandon the above advantages of the same type of magnet section.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a pressure control valve of the present invention having a drooping characteristic.

FIG. 2 is a diagram of a variation of the embodiment of FIG.

FIG. 3 is a vertical cross-sectional view of a pressure control valve of the present invention having an increasing characteristic.

[Explanation of symbols]

10 Magnet Outer Jacket 11 Bottom 12 Core 13 Magnetic Coil 14 Coil Body 15 Adjusting Screw 16 Longitudinal Hole 17 Ball 18 Bearing Pin 19 Magnet Shaft 20 Magnetic Mover 21, 21B Mover Chamber 22 Compression Spring 23 Free End 24 Diaphragm Spring 25 Steps Parts 26, 26B Connection members 27, 27B Distributor casings 29, 29B Longitudinal holes 30, 30B Hole sections 31, 31B Plates with holes 33, 33B Control ring groove 34 Transverse holes 35, 35B Control ring grooves 36, 36B, 37 Lateral holes 39, 39A, 39B Control pistons 40, 41 Piston section 42 Piston neck 43 Addition section 45 Control edge 46 Ring chamber 47 Control edge 50 Lateral holes 52, 53 Inclined holes 55, 56, 57 Piston section 58 Recess 59 Spring 60 blind hole 61 piston neck 62, 63 lateral hole 65 phosphorus Chamber 66 the control edge 67 annular chamber 68 control edge P _r, P _ZU, T connecting portion d _1, d ₂ the diameter

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Werner Brehm, Germany Hemingen Frei Hervon Farnbühlstraße 8 (72) Inventor Walter Freichel Stuttgart Wildenstein Strasse 56 (56) References Kaihei 2-46384 (JP, A) JP 59-37309 (JP, A) JP 63-298415 (JP, A) JP 63-298414 (JP, A) JP 5-126106 ( JP, A) JP 4-205508 (JP, A) Actual development Sho 60-52509 (JP, U) Actual development Sho 63-160482 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16K 31/06-31/11 G05D 16/00

Claims (9)

(57) [Claims] 1. An electromagnetically actuable pressure control valve, in particular for an automatic transmission of a motor vehicle, comprising a pressure medium passage (2
9, 30, 34, 36, 37; 29B, 30B, 52,
53, 36B) and control groove (33, 35; 33B, 35)
B) with a distributor casing (27; 27B) with a control piston (39; 39A; 39) inside thereof.
B) is movably arranged and the control piston (3
9; 39A; 39B) can be actuated directly via the magnetic armature (19, 20) and the distributor casing (27;
27B) and has at least two piston sections (40, 41; 40A, 41A; 55, 56, 57) which cooperate closely with them, between which section the consumer is under controlled pressure. The pressure medium passage (37; 53) for loading is open and the first piston section (40 , 56) is connected to the inlet connection.
First control for controlling the pressure medium connection to the section (34, 52)
The first control edge having an edge (45, 66)
(45, 66) are the first control ring grooves (33, 33B)
Working together, the second piston section (41, 55) is connected back
Second control for controlling pressure medium connection to section (36, 36B)
Has a control edge (47, 68) and has a second control edge.
J (47, 68) is the second control ring groove (35, 35B)
In the form of cooperating with the control edges (45, 47; 66, 68)
And has two pistons segment (40,41; 40A, 41
A; 55, 56) have a have different diameters, the first system
Control edge (45, 66) and second control edge (47, 6)
The distance between the first control ring groove (33, 33)
Distance between B) and the second control ring groove (35, 35B)
Electromagnetically actuatable pressure control valve, characterized by being larger than . 2. A pressure medium passage for loading a consumer machine.
At (37,53), the controlled pressure is the first control
Constricted inflow at the edge (45, 66) and second regulation
Between the narrowed outflow at the edge (47,68)
The pressure control valve according to claim 1, wherein the pressure control valve is adjustable according to a balance state . 3. The actuating part (19) of the magnetic armature is provided with a control piston (39; 39) by the action of a spring member (22).
The pressure control valve according to claim 1 or 2, wherein the pressure control valve is pressed against A; 39B). 4. A large diameter piston section (41,41)
A) has a control piston (3) on the magnetic mover (20) side.
9; 39A), the pressure control valve according to any one of claims 1 to 3. 5. A large diameter piston section (55)
It is formed on the control piston (39B) on the side opposite to the magnet armature (19, 20), and also on the control piston (39B).
B) has a magnetic armature (19, 2) at its free end face.
Pressure control valve according to any one of claims 1 to 4, characterized in that it is loaded by a force in the direction 0). 6. A force acting on the control piston (39B) is caused by a spring member (59), and a position immovable portion of the pressure control valve serves as a corresponding bearing body with respect to the spring member (59). The pressure control valve according to claim 5, which is useful. 7. The force acting on the control piston (39B) is caused by a pressure load.
The pressure control valve according to claim 5. 8. The magnetic armature (20) is a disk armature, the armature (20) being fixedly arranged on an axis (19) extending coaxially to the control piston. The pressure control valve according to any one of claims 1 to 7. 9. The magnetic armature (19, 20) has at least one
9. The pressure control valve according to claim 1, wherein the pressure control valve is mounted in the magnet housing (10) via two substantially disc-shaped diaphragm springs (24).