JP7627490B2 - Linear Solenoid Valve - Google Patents

Description

The present invention relates to a linear solenoid valve.

Conventionally, some automatic transmissions in vehicles are equipped with linear solenoid valves for hydraulic control. The linear solenoid valve is composed of an electromagnetic part that constitutes a magnetic drive device, and a pressure regulating part that controls hydraulic pressure based on the drive of the electromagnetic part. The pressure regulating part includes a cylindrical sleeve having multiple fluid passages in its cylindrical wall, and a spool that is a skewer-shaped valve body provided inside the sleeve. The electromagnetic part includes a core and a coil. By passing electricity through the coil, the spool is moved back and forth within the sleeve to open and close the fluid passage. In the linear solenoid valve, a configuration is widely adopted in which a flange formed on one end of the sleeve is crimped and fixed to one end of a case that holds the core and coil. As an example of such a configuration, Patent Document 1 discloses a configuration for positioning the sleeve, in which a protrusion protruding toward the sleeve is provided on a bobbin that seals the coil with resin, and the protrusion is engaged with a notch formed in the flange of the sleeve.

JP 2011-133047 A

However, in the configuration disclosed in Patent Document 1, the notch formed in the sleeve flange penetrates the sleeve in the axial direction and opens onto the outer circumferential surface, which means that there is a risk of foreign matter entering the case from the outside through the notch, reducing the reliability of the product.

When the sleeve is molded by die casting, a slide pin that gives the inner shape of the sleeve is inserted between the upper and lower dies that give the outer shape of the sleeve to form a cylindrical cavity, and molten metal is injected into the cavity at high temperature and pressure. To provide a notch in the flange of the sleeve, a through hole that penetrates the axial direction is usually formed in the part that will become the flange during die casting, and after die casting, the outer periphery is cut and removed to open the through hole on the outer periphery. In this method, a part of the slide pin must be abutted against the upper or lower die to form the through hole during die casting. This makes the molding die more susceptible to deterioration, and increases manufacturing costs. In addition, when cutting and removing the outer periphery, when the cutting bit reaches the through hole, intermittent cutting is performed in which the bit repeatedly goes between a state of not abutting the cutting target and a state of abutting it. This reduces molding accuracy and shortens the life of the bit, increasing manufacturing costs.

The present invention was made in light of this background, and aims to provide a linear solenoid valve that improves product reliability and reduces manufacturing costs while maintaining sleeve assembly accuracy.

One aspect of the present invention is a linear solenoid valve including a sleeve having a fluid passage in a cylindrical wall, a spool provided within the sleeve so as to be capable of reciprocating in an axial direction, a core and a coil constituting a linear solenoid, and a case for holding the core and the coil, the linear solenoid being configured to move the spool in the axial direction to change a communication state of the fluid passage,
The case is cylindrical with one end open and one end closed,
the coil is resin-sealed by a sealing portion having a protrusion protruding toward the sleeve,
the sleeve has a recess that opens toward the protrusion at an end on the coil side and is closed at least on the side opposite to the protrusion and on the radially outer side of the sleeve, and is fixed to the end on the opening side of the case with the protrusion engaged with the recess,
a sleeve flange portion having an enlarged diameter and in which the recess is formed is provided at an end of the sleeve on the coil side, the sleeve flange portion being inserted into the case and crimped to an end of the case on an opening side,
The core has a core flange portion that is expanded in diameter at the end on the sleeve side, the core flange portion is located between the sleeve flange portion and the coil, and a core cutout portion is provided by cutting out a portion of the core flange portion, and the protrusion portion engages with the recess via the core cutout portion in this linear solenoid valve.

In the linear solenoid valve, the sleeve is positioned circumferentially by engaging a protrusion provided on the sealing portion of the coil with a recess formed on the end of the sleeve. The recess is closed on the side opposite the protrusion and on the radially outer side of the sleeve, preventing foreign matter from entering the case from the outside through the recess, improving the reliability of the product.

In addition, if the sleeve is misaligned in the circumferential direction during assembly, the protrusion will not fit into the recess and the sleeve will be pushed up. As a result, misalignment can be easily detected visually, preventing the sleeve from being attached in a misaligned state in the circumferential direction and improving the assembly accuracy of the sleeve.

In addition, because the recess is closed on the side opposite the protrusion, there is no need to abut a part of the slide pin against the upper or lower die to form the recess when molding the sleeve by die casting. This prevents deterioration of the molding die and keeps manufacturing costs down. In addition, because the recess is closed on the radially outer side, when cutting and removing the outer periphery after die casting, the cutting tool does not reach the recess, allowing continuous cutting to be maintained. This allows the tool's life to be extended while maintaining molding precision, and reduces manufacturing costs.

As described above, the above aspect provides a linear solenoid valve that maintains the assembly accuracy of the sleeve while improving product reliability and reducing manufacturing costs.

FIG. 2 is a vertical cross-sectional view of the linear solenoid valve according to the first embodiment. FIG. 2 is an exploded perspective view of the linear solenoid valve according to the first embodiment, excluding a spool. FIG. 4 is a side view of a sealing portion in the first embodiment. FIG. 4 is a top view of a sealing portion in the first embodiment. FIG. 2 is a partially enlarged perspective view of the linear solenoid valve according to the first embodiment.

One end of the sleeve is provided with a sleeve flange portion that is enlarged in diameter and has the recess formed therein, and the sleeve flange portion is preferably inserted into the case and crimped to the end of the case on the opening side. In this case, it is easy to secure an area for forming the recess, and the sleeve can be reliably fixed by crimping the sleeve via the sleeve flange portion.

The core has a core flange portion with an expanded diameter at the end on the sleeve side, the core flange portion being located between the sleeve flange portion and the coil, and a cutout portion formed by cutting out a portion of the core flange portion is provided, and the protrusion portion engages with the recess portion via the cutout portion. If the protrusion portion were located radially outward of the core flange portion to prevent the protrusion portion from interfering with the core flange portion, the physical size of the linear solenoid would increase, but the above configuration with the core cutout portion makes it possible to prevent interference between the protrusion portion and the core flange portion without increasing the physical size.

The sealing portion has a connector portion that holds a connection terminal that is electrically connected to the coil, and a case cutout portion is formed at the end of the opening side of the case so as to expose the connector portion, and the protrusion portion is preferably formed on the connector portion. In this case, it is easier to ensure an area for providing the protrusion portion on the sealing portion, and it is easier to check the engagement state between the protrusion portion and the recess of the sleeve when visually inspecting from the connector portion side during assembly, improving assembly workability.

(Embodiment 1)
An embodiment of the above-mentioned linear solenoid valve will be described with reference to FIGS.
The linear solenoid valve 1 of the present embodiment includes a sleeve 10, a spool 20, a linear solenoid 30, and a case 40.
The sleeve 10 has a fluid passage 15 in its cylindrical wall.
The spool 20 is provided within the sleeve 10 so as to be capable of reciprocating in the axial direction Y.
The linear solenoid 30 is composed of a core 31 and a coil 32 .
The case 40 holds the linear solenoid 30 .
The linear solenoid 30 is configured to be able to change the communication state of the fluid passage 15 by moving the spool 20 in the axial direction Y.

Furthermore, the case 40 has a cylindrical shape with a bottom and one end 41 that is open.
The coil 32 is resin-sealed by a sealing portion 34 having a protrusion 33 that protrudes toward the sleeve 10 .
The sleeve 10 opens toward the protrusion 33 at the end 11 on the coil 32 side, and has a recess 13 that is closed at least on the side opposite the protrusion 33 and on the radially outer side of the sleeve 10, and is fixed to the open end 41 of the case 40 with the protrusion 33 engaged with the recess 13.

The linear solenoid valve 1 of this embodiment will be described in detail below.
The linear solenoid valve 1 can be used in a linear solenoid assembly for controlling an automatic transmission of a vehicle, or an oil control valve used in a variable valve timing mechanism for controlling the engine output of an automobile or the like.

As shown in FIG. 1, the linear solenoid valve 1 of this embodiment has a configuration in which the spool 20 moves back and forth within the sleeve 10 to open and close the fluid passage 15 by utilizing the magnetic force generated by conducting power supplied from a battery (not shown) to the coil 32 provided around the core 31. Note that in this embodiment, the axial direction of the central axis 20a of the spool 20 is defined as Y, and in the axial direction Y, the direction from the linear solenoid 30 toward the sleeve 10 is defined as the upward direction Y1, the opposite direction is defined as the downward direction Y2, and the direction perpendicular to the axial direction Y is defined as the radial direction X.

In this embodiment, as shown in FIG. 1, the core 31 provided in the linear solenoid 30 has a first core 311, a second core 312, and a magnetic shielding portion 313. The first core 311 is made of a magnetic material and is cylindrical, and has a core flange portion 314 at the upper end Y1 that expands in the radial direction X. The upper surface 314a of the core flange portion 314 is flat. The second core 312 is also made of a magnetic material and is cylindrical, and is coaxially provided on the other end side of the first core 311 in the axial direction Y. The magnetic shielding portion 313 is made of a non-magnetic material and is ring-shaped, and is interposed between the first core 311 and the second core 312. In this embodiment, the first core 311, the second core 312, and the magnetic shielding portion 313 are integrated into one part.

As shown in Figures 1 and 2, the core flange portion 314 is formed with a core cutout portion 315 so that the core flange portion 314 does not interfere with the protrusion portion 33 provided on the sealing portion 34 described below. The shape of the core cutout portion 315 is not particularly limited as long as it is a shape that prevents interference with the protrusion portion 33 in the correct assembly mode. In addition, the method of forming the core cutout portion 315 is not particularly limited, but in this embodiment, it is formed by pressing, which prevents burrs from occurring in the core cutout portion 315.

As shown in FIG. 1, a plunger 316 that constitutes a movable iron core is inserted inside the core 31. The plunger 316 is formed with an oil passage 316a that passes through it along the axial direction Y to allow the lubricating oil to flow.

In this embodiment, as shown in FIG. 1, the coil 32 is wound around a resin bobbin 321 and sealed with resin by a sealing portion 34 to form a cylindrical shape. The coil 32 is provided with a connection terminal 35 for supplying power from the outside by conducting the coil 32. As shown in FIGS. 1 and 2, the sealing portion 34 has a connector portion 36 that holds the connection terminal 35. The connector portion 36 is formed to protrude outward in the radial direction X from the sealing portion 34. The connector portion 36 is cylindrical and has an opening 342 that opens downward Y2. The connection terminal 35 is exposed inside the opening 342. A terminal for supplying power is inserted into the opening 342 and connected to the connection terminal 35, so that power is supplied to the coil 32.

As shown in Figures 1 to 3, the sealing portion 34 has a protrusion 33 that protrudes toward the sleeve 10. In this embodiment, the protrusion 33 protrudes from the upper Y1 end face of the connector portion 36 in the sealing portion 34. In this embodiment, one protrusion 33 is provided, but this is not limited thereto, and multiple protrusions 33 may be provided.

As shown in Figures 1, 2 and 5, a sleeve 10 is provided above the sealing portion 34 on the Y1 side. The sleeve 10 is cylindrical and has a plurality of fluid passages 15 in the cylindrical wall. A recess 13 is provided at the end 11 of the sleeve 10 on the coil 32 side, i.e., the lower Y2 side, at a position facing the protrusion 33. In this embodiment, a sleeve flange portion 12 is formed at the end 11 of the sleeve 10 by expanding the diameter, and the sleeve flange portion 12 is provided with a recess 13. As shown in Figures 1 and 2, the recess 13 is formed on the lower surface 12a of the sleeve flange portion 12 so as to open toward the protrusion 33, and the side opposite the protrusion 33 of the recess 13 is closed. The outer side of the recess 13 in the radial direction X is also closed, and in this example, all of the side circumferential surfaces of the recess 13 are closed. Therefore, the recess 13 is only open to the lower Y2, does not penetrate the sleeve flange portion 12 in the axial direction Y, and does not open to the outer side in the radial direction X. In this example, the lower surface 12a of the sleeve flange portion 12 is a flat surface that extends parallel to the upper surface 314a of the core flange portion 314, ensuring a wide contact area between them. As a result, even if the formation position of the recess 13 is misaligned, the recess 13 is formed in the lower surface 12a, preventing the recess 13 from opening in the radial direction X.

As shown in FIG. 1, a spool 20 is inserted inside the sleeve 10. The spool 20 is rod-shaped, and a number of grooves 21 for opening and closing the fluid passage 15 of the sleeve 10 are formed on the side surface of the spool 20. A spring (not shown) is provided as a biasing member on the upper side Y1 of the spool 20. The spring biases the spool 20 downward Y2. The end 23 of the spool 20 on the lower side Y2 abuts against the plunger 316.

As shown in FIG. 1, the core 31, the sealing portion 34 including the coil 32, and the plunger 316 are housed in the case 40. The core 31 is assembled so that the protrusion 33 of the sealing portion 34 is positioned in the core cutout portion 315 formed in the core flange portion 314. The case 40 is cylindrical with a bottom, and the end portion 41 on the upper Y1 side is open. The peripheral wall of the end portion 41 is thin-walled, and a first step portion 42 is formed on the inner wall surface of the case 40. The first step portion 42 abuts against the core flange portion 314, positioning the core 31 in the axial direction Y.

As shown in Figures 1 and 2, a restricting protrusion 43 is formed on the bottom of the case 40, which protrudes inward from the case 40 and abuts against the lower surface 316b of the plunger 316 to restrict the lower position of the plunger 316. Furthermore, a second step portion 45 is formed in the side wall of the case 40 in the lower Y2 region, which is reduced in the radial direction. The lower surface 34a of the sealing portion 34 abuts against the inner surface of the second step portion 45.

As shown in FIG. 2, the case 40 has a case cutout 44 formed by cutting out a portion of the case 40. As shown in FIG. 1, the connector portion 36 is exposed through the case cutout 44 and is configured to be located outside the case 40.

As shown in FIG. 1, the spool 20 is disposed above Y1 in the axial direction Y of the plunger 316, and the sleeve 10 is disposed above Y1 in the sealing portion 34 with the protrusion 33 of the sealing portion 34 positioned within the recess 13 of the sleeve 10. As a result, the sleeve flange portion 12 formed on the end portion 11 of the sleeve 10 is positioned within the case 40. The end portion 41 of the case 40 above Y1 is crimped inward to press the sleeve flange portion 12 against the sealing portion 34, thereby fixing the sleeve 10 to the case 40.

In the linear solenoid valve 1 configured as described above, the plunger 316 is attracted to the first core 311 by a magnetic field generated by energizing the coil 32 via the connection terminal 35. As a result, the plunger 316 urges the spool 20 upward Y1, and the spool 20 moves upward Y1. Meanwhile, the spool 20 is urged downward Y2 by a spring (not shown) as an urging member provided in the upper Y1. As a result, when the current to the coil 32 is stopped, the urging by the plunger 316 is released, and the spool 20 and the plunger 316 move downward Y2. As a result, the spool 20 can reciprocate in the axial direction Y within the sleeve 10. This controls the open/close state of the fluid passage 15 of the sleeve 10.

Next, the functions and effects of the linear solenoid valve 1 of this embodiment will be described in detail.
In the linear solenoid valve 1 of this embodiment, the sleeve 10 is positioned in the circumferential direction by engaging a protrusion 33 provided on a sealing portion 34 of the coil 32 with a recess 13 formed in an end portion 11 of the sleeve 10. Moreover, since the recess 13 is closed on the side opposite to the protrusion 33 and on the radially outer side of the sleeve 10, foreign matter is prevented from entering the case 40 from the outside through the recess 13, thereby improving the reliability of the product.

In addition, if the sleeve 10 is misaligned in the circumferential direction when it is assembled, the protrusion 33 will not fit into the recess 13 and the sleeve 10 will be pushed up. As a result, it becomes easier to visually detect misalignment, so that the sleeve 10 can be prevented from being attached in a misaligned state in the circumferential direction, improving the assembly accuracy of the sleeve 10.

In addition, since the recess 13 is closed on the side opposite the protrusion 33, there is no need to abut a part of the slide pin against the upper or lower die to form the recess 13 when die-casting the sleeve 10. This prevents deterioration of the molding die and keeps manufacturing costs down. In addition, since the recess 13 is closed on the radially outer side, when cutting and removing the outer periphery after die-casting, the cutting tool does not reach the recess 13 and continuous cutting can be maintained. This makes it possible to maintain the life of the tool while maintaining molding precision, thereby reducing manufacturing costs.

In addition, in this embodiment 1, the end 11 of the sleeve 10 on the coil 32 side has a sleeve flange portion 12 that is enlarged in diameter and has a recess 13 formed therein, and the sleeve flange portion 12 is inserted into the case 40 and crimped to the end 41 on the opening side of the case 40. This makes it easy to ensure an area for forming the recess 13, and by crimping the sleeve 10 via the sleeve flange portion 12, the sleeve 10 can be reliably fixed.

In addition, in this embodiment 1, the core 31 has a core flange portion 314 that is expanded in diameter at the end on the sleeve 10 side, and the core flange portion 314 is located between the sleeve flange portion 12 and the coil 32, and a core cutout portion 315 is provided by cutting out a part of the core flange portion 314. The protrusion portion 33 engages with the recess 13 via the core cutout portion 315. If the protrusion portion 33 were located on the radially outer side of the core flange portion 314 in the X direction so as not to interfere with the core flange portion 314, the size of the linear solenoid 30 would increase, but by using the above configuration with the core cutout portion 315, interference between the protrusion portion 33 and the core flange portion 314 can be prevented without increasing the size.

In addition, in this embodiment 1, the sealing portion 34 has a connector portion 36 that holds a connection terminal 35 that is electrically connected to the coil 32, and a case cutout portion 44 is formed at the end 41 on the opening side of the case 40 so as to expose the connector portion 36, and the protrusion portion 33 is formed on the connector portion 36. This makes it easier to ensure an area for providing the protrusion portion 33 in the sealing portion 34, and also makes it easier to check the engagement state between the protrusion portion 33 and the recess 13 of the sleeve 10 when visually inspecting from the connector portion 36 side during assembly, improving assembly workability.

As described above, this embodiment provides a linear solenoid valve 1 that maintains the assembly accuracy of the sleeve 10 while improving product reliability and reducing manufacturing costs.

The present invention is not limited to the above-described embodiment, and can be applied to various embodiments without departing from the spirit of the present invention.

1...Linear solenoid valve, 10...Sleeve, 12...Sleeve flange portion, 13...Recess, 15...Fluid passage, 20...Spool, 30...Linear solenoid, 31...Core, 32...Coil, 33...Protrusion, 34...Sealing portion, 36...Connector portion, 40...Case, 44...Case cutout portion, 314...Core flange portion, 315...Core cutout portion

Claims (2)

A linear solenoid valve comprising: a sleeve having a fluid passage in a cylindrical wall; a spool provided within the sleeve so as to be capable of reciprocating in an axial direction; a core and a coil constituting a linear solenoid; and a case for holding the core and the coil, wherein the linear solenoid is configured to move the spool in the axial direction to change a communication state of the fluid passage,
The case has a cylindrical shape with one end open and a bottom,
the coil is resin-sealed by a sealing portion having a protrusion protruding toward the sleeve,
the sleeve has a recess that opens toward the protrusion at an end on the coil side and is closed at least on a side opposite to the protrusion and on a radially outer side of the sleeve, and is fixed to an end on the opening side of the case with the protrusion engaged with the recess,
a sleeve flange portion having an enlarged diameter and in which the recess is formed is provided at an end of the sleeve on the coil side, the sleeve flange portion being inserted into the case and crimped to an end of the case on an opening side,
a core flange portion having an expanded diameter at the end portion on the sleeve side, the core flange portion being located between the sleeve flange portion and the coil, and a core cutout portion being formed by cutting out a portion of the core flange portion, the protrusion portion engaging with the recess portion via the core cutout portion . 2. The linear solenoid valve according to claim 1, wherein the sealing portion has a connector portion that holds a connection terminal that is electrically connected to the coil, a case cutout portion that is cut out to expose the connector portion is formed at an end portion of the opening side of the case, and the protrusion portion is formed on the connector portion.

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