KR20120064037A - Slide valve, especially for using in an automatic transmission of a motor vehicle - Google Patents

Abstract

PURPOSE: A slide valve for an automatic transmission of a vehicle is provided to have a short step response in case that an operational connection part is connected to a supply connection part as a hydraulic method. CONSTITUTION: A slide valve(5) for an automatic transmission of a vehicle comprises a valve slide(14). The valve slide is operated in a first direction(16) by an actuator(8) and is operated in a second direction(18) opposite to the first direction by internal pressure of a control chamber(36). The valve slide connects an operational connection part(A) to a supply connection part(P) or a discharge connection part(T) by a recess(20) as a hydraulic method. Hydraulic pressure is tapped at an outlet point(38) in a flowing channel(34) of the slide valve to be supplied to the control chamber. The outlet point is arranged between the supply connection part and the operational connection part.

Description

Sliding valve for automobile automatic transmission {Slide valve, especially for using in an automatic transmission of a motor vehicle}

The invention relates to a slide valve according to the preamble of claim 1.

Electrically actuated solenoid valves, in particular so-called pressure regulating valves (slide valves), used in the automatic transmission of motor vehicles are known in the market. Thus, the couplings of the automatic transmission can be controlled directly. These valves, on the one hand, operate relatively dynamically and allow for large flow rates in a short time. On the other hand the valves are stable and insensitive to interference magnitudes.

Embodiments of the pressure regulating valve include an actuator for operating a valve slide capable of operating a hydraulic unit. The hydraulic unit comprises, for example, one supply connection, one or a plurality of discharge connections and one or more actuation connections, said actuation connections being hydraulically connected to the return connection via an external hydraulic line. The hydraulic return line is used for example to extend through the so-called control plate and to return the working pressure into the control chamber adjacent the valve slide.

For example, the pressure regulating valve operates as follows: In the absence of current in the actuator (no current is supplied to the associated electromagnet), the spring moves the valve slide with the armature to the first end position. In this position, the operative connection is hydraulically connected with the discharge connection. Thus, the pressure regulating valve is closed with no current or without pressure ("normally closed" or "NC"). Upon supply of current to the electromagnet, the armature is moved in the direction of the second end position by a magnetic force against the spring force with the valve slide. During the movement of the valve slide, the actuation connection is hydraulically disconnected from the discharge connection first, and then the actuation connection is connected with the supply connection. Pressure in the supply connection is transmitted to the actuation connection. Since the pressure rise at the actuation connection is transmitted to the return connection via the hydraulic line, the same pressure is created in the control chamber (return chamber, FB-chamber) of the slide valve connected to the return connection. The pressure exerts a pressure acting on the actuator with the valve slide. When the pressure exceeds the magnetic force of the electromagnet with the spring force, the valve slide is moved back in the axial direction so that the supply connection is always hydraulically disconnected from the actuating connection. Thus, a force balance is achieved between the spring force and hydraulic pressure on the one hand and magnetic force on the other hand. Due to this, the pressure in the actuating connection can be adjusted according to the current flowing through the electromagnet to a wide limit.

Patent publications in this field are for example 10 2008 042 624 A1.

It is an object of the present invention to provide a slide valve for an automotive automatic transmission, in particular when the actuating connection is hydraulically connected to the supply connection, having a short step response.

The problem is solved by the slide valve according to claim 1. Preferred embodiments are set forth in the dependent claims. Features important to the invention are shown in the following description and drawings, which are important to the invention, alone and in different combinations, unless explicitly indicated.

The method according to the invention has the advantage that when the actuating connection is hydraulically connected with the supply connection, the slide valve, in particular the pressure regulating valve for the automotive automatic transmission, has a very short step response time. This allows, for example, the coupling of the automatic transmission to be operated quickly and reliably.

The present invention contemplates that the slide valve generally comprises an actuator actuated electromagnetically, the actuator being capable of moving the valve slide in a first direction. The pressure in the control chamber can also move the valve slide in a second direction opposite to the first direction. The slide valve can in this case be embodied as a pressure regulating valve so that a force balance between the actuator on the one hand and the axial force generated by the pressure in the control chamber on the other hand can be achieved. The latter force is usually supported by the force of the valve spring. From this, a predetermined pressure adjustment at the actuation connection is given according to the axial force of the actuator.

The present invention is based on the premise that the higher the pressure in the control chamber, the lower the pressure of the actuator, and conversely, the lower the pressure in the control chamber, the lower the pressure of the actuator. Thus, the hydraulic pressure is tapped and supplied to the control chamber at the outlet point of the flow channel of the slide valve. For a quick supply, the lowest possible pressure in the control chamber is desirable, at least in a short time. The withdrawal point is arranged between the supply connection and the operation connection in the region of the recess extending in the axial direction of the valve slide. The recess substantially forms the flow channel.

If the supply connection and the operating connection are hydraulically connected to each other at the corresponding position or movement of the valve slide, a relatively low oil pressure is given to the draw point. A strong hydraulic flow is given at least temporarily within the flow channel with a relatively low fluid static pressure. This effect is also known, for example, as the "suction jet effect" of water jet pumps. The low pressure is supplied to the control chamber. Since the opening step of the movement of the valve slide is supported by the relatively low pressure produced at this time in the control chamber, the slide valve can quickly create high hydraulic pressure in the actuating connection. The so-called "step response time" is correspondingly short and the dynamics of the slide valve are correspondingly large.

Subsequently, if the supply connection and the operation connection have the same hydraulic pressure, the flow in the flow channel disappears or at least becomes smaller, and the control chamber has approximately the pressure of the operation connection, thus contributing to the adjustment of the predetermined pressure. However, if a pressure rise is required again, this is possible with high dynamics.

If the hydraulic pressure at the "supply connection" is at least temporarily higher than the pressure at the "actuating connection", the connections can be any hydraulic connection of the slide valve with any function.

In an embodiment of the slide valve, a channel from the draw point to the control chamber is arranged in the housing of the slide valve. The channel forms a return line between the flow channel or the draw point and the control chamber. By the arrangement of the channels in the housing of the slide valve, the leakage can be kept particularly small, so that the function of the slide valve is improved. The withdrawal point is fixed with respect to the housing of the slide valve.

In another embodiment of the slide valve, the channel from the draw point to the control chamber is disposed in the valve slide. Thus, the channel is particularly simple and can be advantageously implemented in flow technology. In addition, leakage can be minimized. Furthermore, the valve design thus far can be reformed into the slide valve according to the invention at low cost. The withdrawal point is fixed in relation to the valve slide.

In another embodiment of the slide valve, the channel from the draw point to the control chamber is disposed outside the housing of the slide valve. For example, the channel may be formed in the hydraulic control plate of the automatic transmission, thereby making the manufacture of the slide valve inexpensive.

In addition, end sections of one or more holes, which are not used in the channel, are caulked by balls. Due to this, the channel can simply be produced by holes facing in the axial and radial directions, and the end sections not in use are hydraulically sealed by one or more balls. Therefore, the slide valve becomes inexpensive.

If the recess in the housing and / or the wall portion opposite it is formed to minimize the pressure at the draw point in the fluid flow from the supply connection to the operative connection, the dynamic properties of the slide valve are improved. Methods for this are already known in the field of hydraulic systems. For example, the hydraulic pressure and the flow rate occurring in the slide valve or the recess are calculated by simulation, so that the structure of the slide valve can be optimized. The goal of this simulation is to minimize the fluid static pressure given at the draw point (“low pressure”) and to correspondingly maximize the dynamics of the slide valve, especially during the hydraulic connection between the supply connection and the operating connection.

In an embodiment of the slide valve, a hydraulic connection is formed between the supply connection and the actuating connection when no current is supplied to the electromagnet. Alternatively, a hydraulic connection is formed between the discharge connection and the operating connection when no current is supplied to the electromagnet. When no current is supplied to the electromagnet or in the inactive state of the actuator, the valve slides are moved to and held in corresponding axial positions, respectively, by the force of the valve spring. For this reason, the present invention can be applied to different basic embodiments of the slide valve or to different basic embodiments of the hydraulic control of the automatic transmission. In addition, the present invention can be applied to a slide valve having a characteristic curve that is at least partly "rising" or at least partly "falling".

According to the invention, there is provided a slide valve for an automotive automatic transmission, in particular when the actuating connection is hydraulically connected with the supply connection, with a particularly short step response.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a partial cross-sectional view of a first embodiment of a slide valve having a channel in a housing of the slide valve;
FIG. 2 is a second embodiment of a slide valve similar to FIG. 1; FIG.
3 is a partial cross-sectional view of a third embodiment of a slide valve having channels in the valve slide of the slide valve;
4 is a partial cross sectional view of a fourth embodiment of a slide valve having channels outside the housing of the slide valve;
5 is a step response of pressure at the operative connection of the slide valve of FIGS.

Members and sizes having the same function in all the drawings are denoted by the same reference numerals in different embodiments.

1 shows a slide valve 5 for hydraulically actuating a coupling device of an automatic transmission of a motor vehicle. The slide valve 5 comprises a housing 6, in which an actuator 8 is arranged in the region on the right side of the drawing, which actuator here is embodied as an electromagnet 8. The slide valve 5 also comprises a housing section 7 which is not described in detail here. The slide valve 5 and the members included in the slide valve 5 are implemented substantially rotationally symmetric about the longitudinal axis 15.

The electromagnet 8 comprises a coil 9 and an actuator 10, which can be pulled to the left in the drawing by the extreme core 11 when supplying current to the coil 9. The armature 10 is engaged with the valve slide 14 disposed in the housing 6 and movable in the axial direction by the engaging member 12 and the engaging pin 13. The valve slide 14 is shown in the axial center position in the center and left regions of the figure. Arrow 16 indicates the first axis direction, and arrow 18 indicates the second axis direction.

The valve slide 14 comprises an axially extending radial recess 20, in the form of a stepped constriction, in which the actuation connection A is alternatively a supply connection P or an outlet connection. It can be hydraulically connected to (T). The supply connection P, the operation connection A and the discharge connection T are hydraulically connected with respective ring chambers 22, 24, 26 formed in the housing 6. However, these connections are not clearly shown in the cross-sectional view shown in FIG. Three arrows 30, 31 and 32 indicate the direction of hydraulic flow through the connections. By the recesses 20 a flow channel 34 is formed in the radially inner section of the housing 6. In addition, the slide valve 5 comprises two discharge connections T1 and T2 for discharging the leakage.

The ring chamber in the left region of the slide valve 5 in the figure forms the control chamber 36. The control chamber 36 is in particular limited by the pressure plane (unreferenced) of the valve slide 14 disposed on the left and right sides of the ring groove 37 in the valve slide 14 in the figure. The right pressure side is larger than the left pressure side.

The control chamber 36 is hydraulically connected to the outlet point 38 of the flow channel 34 via a radial hole, an axial hole and a radial hole (not shown respectively) of the housing 6. The lead point 38 is arranged between the supply connection P and the operative connection A in the axial direction of the valve slide 14 in the region of the recess 20. The radial and axial holes together form a channel 40 and are hydraulically sealed caulked by balls 42 at their unused end sections, respectively. The axial hole was drilled through the cutout 44 of the housing 6.

The end section on the left side in the view of the valve slide 14 is moved to the right in the view by the valve spring 46. The valve spring 46 is supported by the press-in end portion 48 of the housing 6. Overall, the leakage of the slide valve 5 of FIG. 1 due to the channel 40 integrated into the housing 6 is relatively small. The wall portion of the recess 20 and the housing 6 opposite it, shown in FIG. 1, are optimized to minimize fluid static pressure at the draw point 38 in fluid flow from the supply connection P to the operative connection A. FIG. do.

When no current is supplied to the electromagnet 8, the valve slide 14 is moved to the right as seen in the drawing by the force of the valve spring 46 (arrow 18), and the actuating connection A is connected to the ring chamber 26. Or hydraulically connected to the outlet connection (T). The discharge connection T has no hydraulic pressure or a relatively low hydraulic pressure. Therefore, the pressure at the operating connection A is also low. That is, the slide valve 5 is closed in the absence of electric current.

When a current is supplied to the electromagnet 8, the actuator 10 is pulled by the magnetic force of the extreme core 11 to the left (arrow 16) as seen in the drawing. The engagement pin 13 transfers this force to the valve slide 14, which is first moved in the direction of the arrow 16. When the flow channel 34 is hydraulically connected with the ring chamber 22, hydraulic flow from the supply connection P to the operation connection A takes place. The supply connection P has a relatively high hydraulic pressure. Thus, the flow velocity at the draw point 38 is high and the fluid static pressure is low, thus correspondingly low in the channel 40.

The low pressure in the channel 40 is transmitted to the control chamber 36. Since the pressure face disposed on the right side of the ring groove 37 in the figure is larger than the pressure face on the left side, there arises an axial force toward the left as seen in the figure, thereby supporting the action of the electromagnet 8. Due to this, the movement of the valve slide 14 in the direction 16 is accelerated, and the actuation connection A can in particular be quickly connected with the supply connection P in a large cross section, the supply connection P being a slide. Open the valve (5) quickly. In this state, the slide valve 5 operates as a pressure regulating valve, and on the one hand the axial force generated by the force of the valve spring 46 and the pressure in the control chamber 3, and on the other hand the electromagnet ( Force equilibrium may occur between the magnetic forces in 8).

5 shows the step response of the pressure 60 at the actuation connection A of the slide valve 5. The pressure 60 is shown on the longitudinal axis of the coordinate system along with the current I flowing through the coil 9. The horizontal axis shows the time t. The first broken line 62 represents the rated value of the current I, and the second broken line 64 represents the set value of the pressure 60. 5 shows the hydraulic profile over time, for example in an actuator of a coupling of an automatic transmission.

From the time point t1, the current I is supplied to the coil 9. After the elapse of the dead time, the pressure 60 rapidly rises to the first value 66 at time t2 and then continues to rise to the second value 68 until time t3. At the time point t3, the pressure 60 rapidly rises to the set value 64. The time between the time point t1 and the time point t3 is referred to as the "step response time" of the slide valve 5.

From the time point t3 the setpoint 64 of the pressure 60 is achieved and the hydraulic flow in the flow channel 34 is substantially lost. Then, the pressure in the channel 40, and thus in the control chamber 36, has approximately the hydraulic pressure at the actuation connection A. This allows the slide valve 5 to adjust the pressure at the actuation connection A in the manner of a known pressure regulating valve in accordance with the current I flowing through the coil.

FIG. 2 shows a second embodiment similar to FIG. 1 of the slide valve 5. Unlike FIG. 1, the ring chamber 52 housing the valve spring 46 is enlarged radially so that an axial hole (not shown) of the channel 40 can be drilled through the ring chamber 52. have. Thus, the cutout 44 is not necessary. The housing 6 and the end portion 48 are adjusted accordingly. The functional members of the slide valve 5 of FIG. 2 are the same as those of FIG. 1.

3 shows an embodiment of a slide valve 5 in which a channel 40 from the draw point 38 to the control chamber 36 is arranged in the valve slide 14. The valve slide 14 is shown here in cross section. The control chamber 36 is hydraulically connected to the outlet point 38 of the flow channel 34 via two radial holes and one axial hole (not shown respectively) of the valve slide 14. The radial holes and the axial holes together form a channel 40. Since the draw point 38 is a member of the valve slide 14, unlike FIGS. 1 and 2, it can move with the valve slide. The outlet point 38 is here embodied as a tubular portion 54 radially disposed on the valve slide 14. In this way, the outlet point 38 or the inlet of the tubular part 54 can be arranged in a relatively sealed manner in the radially inner wall part of the housing 6.

In FIG. 3 the cross section of the housing 6 is selected such that the channel (without reference numerals) forming the supply connection P, the operation connection A and the discharge connection T is visible. The remaining members of the slide valve 5 are similar or identical to the corresponding members of FIGS. 1 and 2.

4 shows an embodiment of a slide valve 5 in which a channel 40 from the draw point 38 to the control chamber 36 is arranged outside the housing 6 of the slide valve 5. Channel 40 is connected to control chamber 36 or flow channel 34 via radial connections 56 and 58. Channel 40 can be, for example, a channel or a discrete hydraulic line in a control plate of an automatic transmission. The remaining members of the slide valve 5 are similar or identical to the corresponding members of FIG. 1 or 2.

1 to 4 show that the slide valve 5 is " closed without current ", ie the actuating connection A is hydraulically disconnected from the supply connection P when no current is supplied to the electromagnet 8; )to be. Of course, for example, by replacing the supply connection P with the discharge connection T and by deforming the recess 20 and changing the arrangement of the withdrawal points 38, the slide valve 5 is implemented "open without current". It is also possible. In this case, when no current is supplied to the electromagnet 8, the operation connecting portion A is hydraulically connected to the supply connecting portion P. However, this is not shown in Figures 1-4.

5 slide valve
6 housing
8 actuator
14 valve slide
20 recess
34 flow channels
36 control chamber
38 draw points
40 channels
42 balls
A operating connection
P supply connection
T outlet connection

Claims (8)

In particular, it comprises a valve slide 14 operable by the actuator 8 in a first direction 16 and in a second direction 18 opposite to the first direction by a pressure in the control chamber 36. As a slide valve (5) for use in automotive automotive transmissions, the valve slide (14) can hydraulically connect the actuation connection (A) to the supply connection (P) or the discharge connection (T) by means of a recess (20). In the slide valve, the hydraulic pressure is tapped at the outlet point 38 in the flow channel 34 of the slide valve 5 and supplied to the control chamber 36.
The draw point 38 is characterized in that the slide is arranged between the supply connection P and the actuating connection A when viewed in the axial direction of the valve slide 14 in the region of the recess 20. valve. 2. Slide valve according to claim 1, characterized in that a channel (40) from the draw point (38) to the control chamber (36) is arranged in the housing (6) of the slide valve (5). 2. Slide valve according to claim 1, characterized in that a channel (40) from the draw point (38) to the control chamber (36) is arranged in the valve slide (14). 2. Slide valve according to claim 1, characterized in that a channel (40) from the draw point (38) to the control chamber (36) is arranged outside the housing (6) of the slide valve (5). 4. Slide valve according to claim 2 or 3, characterized in that the end sections of one or more holes which are not used in the channel (40) are caulked by balls (42). The wall portion of the recess (20) and / or the housing (6) facing the recess is connected to the actuating connection (A) from the supply connection (P). A slide valve, characterized in that it is formed to minimize the pressure at the withdrawal point (38) during fluid flow to the). 7. A hydraulic connection according to any one of the preceding claims, characterized in that a hydraulic connection is formed between the supply connection (P) and the actuating connection (A) when no current is supplied to the electromagnet (8). Slide valve. 8. The hydraulic connection according to claim 1, wherein a hydraulic connection is formed between the discharge connection part T and the operation connection part A when no current is supplied to the electromagnet 8. Slide valve.

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