CN117847237A - Valve device - Google Patents

Abstract

A valve device includes a drive gear (15) made of resin at one end of a valve shaft, and the drive gear (15) includes a detection object (21) of an induction sensor, wherein the drive gear (15) includes a metal rod member (33) integrated with the detection object (21) by insert molding in a state in which a center portion is exposed at one side surface, an exposed portion (38) of the rod member (33) in the drive gear (15) is abutted against an end portion of the valve shaft (10) and fixed by laser welding from an outer hole (39) at a back side of the abutted portion, thereby constituting a valve shaft unit (30), and the rod member (33) is provided with a circular arc hole (52) extending in a circumferential direction at a radially outer side of a welding position welded with the end portion of the valve shaft.

Description

Valve device

Technical Field

The present invention relates to a valve shaft and gear fixing structure in a valve device.

Background

Valves such as a throttle valve often have a flow path formed in a housing, and a valve body for opening and closing the flow path is fixed to a valve shaft and is configured to be driven by a rotary actuator such as an electric motor. A speed reducer is provided between the rotary actuator and the valve shaft, and a driving gear is provided on the valve shaft as a part of the speed reducer.

For example, in the valve device described in patent document 1, a valve shaft is inserted into and fixed to a hole provided in a driving gear, but in a mounting portion of the valve shaft and the driving gear, the valve shaft and the driving gear are fixed by tightening a nut by making a cross section of the valve shaft and the hole of the driving gear rectangular, for example, so that a rotational driving force can be transmitted between the valve shaft and the driving gear.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2014-105691

Disclosure of Invention

Technical problem to be solved by the invention

Here, in order to simplify the mounting structure of the valve shaft and the driving gear, it is conceivable to fix the valve shaft and the driving gear by welding, for example.

In the case where the driving gear is made of resin, the driving gear and the valve shaft made of metal cannot be welded. For this reason, for example, a structure in which a metal support body is previously incorporated in a driving gear by insert molding or the like, and the support body and the metal valve shaft are fixed by welding with a laser or the like may be considered.

However, in the drive gear including the metal support body by insert molding, there is a possibility that a portion around the welded portion of the drive gear may be deformed by heat when the support body and the valve shaft are welded.

The present invention has been made in view of the above-described problems, and provides a valve device configured to suppress thermal influence on a gear when fixing a drive gear and a valve shaft by welding.

Technical proposal adopted for solving the technical problems

In order to achieve the above object, a valve device according to the present invention includes a resin plate-shaped gear at one end of a metal shaft for driving a valve element, wherein the gear includes a metal support member integrated by insert molding in a state in which at least a part of the gear is exposed at one side surface, an exposed portion of the support member in the gear and an end portion of the shaft are welded to each other to form a shaft unit, and a hole portion extending in a circumferential direction is provided in the support member radially outside a welding position where the support member and the end portion of the shaft are welded to each other.

Preferably, the hole is a hole into which a protrusion of a molding die of the gear is inserted to hold the support member during the insert molding.

Preferably, the protruding portion protrudes forward in the insertion direction through the support member when the protruding portion is inserted into the hole portion during the insert molding process, and the protruding portion is spaced radially outward and inward.

Preferably, the gear further includes a detection object including a non-contact sensor for detecting a rotation angle of the shaft, and the detection object is integrated with the gear by the insert molding process together with the support member.

Preferably, the protrusion of the molding die penetrating the support member supports the object to be inspected during the insert molding process.

Preferably, the valve device is a throttle valve that controls an intake air amount of the internal combustion engine.

According to the valve device of the present invention, the gear fixed to the shaft that drives the valve element is insert-molded so as to include the metal support member. The exposed portion of the support member in the gear including the support member and the end portion of the shaft are welded to form a shaft unit. Further, since the support member is provided with the hole portion extending in the circumferential direction radially outward of the welding position where the end portion of the shaft is welded, it is difficult for welding heat to be transmitted radially outward from the welding position radially inward of the hole portion when the support member and the shaft are welded. Therefore, at the time of welding the support member and the shaft, heat is less likely to be transmitted to the gear radially outside the hole, and thermal deformation of the resin gear can be suppressed.

Drawings

Fig. 1 is a perspective view of a valve device according to an embodiment of the present invention.

Fig. 2 is a longitudinal sectional view of the valve device of the present embodiment.

Fig. 3 is a perspective view of the valve shaft unit.

Fig. 4 is a diagram showing components of the drive gear in the valve shaft unit.

Fig. 5 is a perspective view of the drive gear in the valve shaft unit.

Fig. 6 is a perspective view of the drive gear and the valve shaft in the valve shaft unit.

Fig. 7 is an explanatory diagram showing a method of fixing the drive gear and the valve shaft.

Fig. 8 is an explanatory diagram showing a positional relationship between the lever member and the subject.

Fig. 9 is a front view showing the shape of the lever member.

Fig. 10 is an explanatory diagram of a method of manufacturing a drive gear.

Detailed Description

An embodiment of the present invention will be described below with reference to the drawings.

Fig. 1 is a perspective view of a valve device 1 according to an embodiment of the present invention. Fig. 2 is a longitudinal sectional view of the valve device 1 of the present embodiment. Fig. 2 is a cross-sectional view of the portion A-A shown in fig. 1.

The valve device 1 according to an embodiment of the present invention is, for example, a throttle valve, and is provided in an intake passage of an internal combustion engine to control an intake air amount.

As shown in fig. 1 and 2, the valve device 1 includes an electric motor 4 and a speed reducer 5 in a housing 3 in which a fluid passage 2 that is a part of an intake passage is formed. The valve device 1 further includes: a valve element 6 for opening and closing the fluid passage 2; and a valve shaft 10 (shaft) rotatably supported by the housing 3 and disposed so as to intersect the fluid passage 2. Valve shaft 10 is fixed with valve element 6.

The speed reducer 5 is composed of a motor gear 11 fixed to an output shaft of the electric motor 4, an intermediate gear 12 rotatably supported by the housing 3, and a drive gear 15 (gear) fixed to an end portion of the valve shaft 10, and power is transmitted from the electric motor 4 in the order of the motor gear 11, the intermediate gear 12, and the drive gear 15 to drive the valve shaft 10 to rotate.

A return spring 16 is included adjacent to the drive gear 15 near one end of the valve shaft 10. The return spring 16 is a torsion coil spring wound around the valve shaft 10, and has one end engaged with the drive gear 15 and the other end engaged with the housing 3. The return spring 16 biases the valve shaft 10 in one rotational direction.

The housing 3 includes two stoppers, not shown, which are in contact with the drive gear 15. The rotation angle of the valve shaft 10 is limited to a range of a prescribed angle (for example, 90 degrees) by the stopper.

When the electric motor 4 is not energized, the valve shaft 10 is rotated by the biasing force of the return spring 16, and the fluid passage 2 is fully closed (or fully opened) by the valve element 6. By energizing the electric motor 4, the valve shaft 10 rotates against the urging force of the return spring 16, and the valve element 6 is rotated to adjust the amount of intake air flowing through the fluid passage 2.

At one end portion of the valve shaft 10 on the drive gear 15 side, an induction sensor 20 (non-contact sensor) that detects a rotation angle (rotation position) of the valve shaft 10 is included.

The induction sensor 20 includes: a metal object 21 provided on the drive gear 15; and a sensor body 22 fixed to the housing 3 and disposed so as to be close to and face the object 21.

The sensor body 22 of the induction sensor 20 includes, for example, a sensor coil through which a current flows to generate a high-frequency magnetic field, and detects the inductance of the sensor coil that changes due to the movement of the object in the magnetic field, thereby detecting the rotation angle of the valve shaft 10.

Fig. 3 is a perspective view of the valve shaft unit 30. Fig. 4 is a diagram showing components of the drive gear 15 in the valve shaft unit 30. Fig. 5 is a perspective view of the drive gear 15 in the valve shaft unit 30. Fig. 6 is a perspective view of the drive gear 15 and the valve shaft 10 in the valve shaft unit 30. Fig. 7 is an explanatory diagram showing a method of fixing the drive gear 15 and the valve shaft 10. Fig. 7 is a longitudinal sectional view of the fixed portion of the drive gear 15 and the valve shaft 10. Fig. 8 is an explanatory diagram showing a positional relationship of the object to be detected with respect to the lever member. Fig. 9 is a front view showing the shape of the lever member. Fig. 10 is an explanatory diagram of a method of manufacturing the drive gear 15. In addition, fig. 10 is a longitudinal sectional view through the central hole of the lever member.

As shown in fig. 3 and 4, the valve shaft unit 30 is composed of the valve shaft 10 made of metal and the drive gear 15. The drive gear 15 is composed of a gear portion 31 made of resin, the object 21 of the induction sensor 20, and a lever member 33 (support member) made of metal.

The gear portion 31 is a substantially disk-shaped member formed of resin, and a gear 35 (for example, a spur gear) is formed in a range of substantially half (substantially 180 degrees) of the outer peripheral end. At both circumferential ends of the outer peripheral portion where the gear 35 is formed, stopper abutment surfaces 36 are provided, respectively, which abut against a stopper, not shown, included in the housing 3 and restrict rotation. A circular shaft mounting hole 37 (insertion hole) into which the valve shaft 10 is inserted is provided in the center of the inner side surface (surface opposite to the surface facing the sensor body 22: one side surface of the present invention) of the gear portion 31 (see fig. 7). In addition, the diameter of the shaft mounting hole 37 is slightly larger than the outer diameter of the valve shaft 10. The central portion of the lever member 33 is exposed inside the shaft mounting hole 37 (an exposed portion 38 shown in fig. 7).

An outer hole 39 (exposure hole) having a smaller diameter than the shaft mounting hole 37 and larger than the valve shaft 10 is provided in the center of the outer side surface (surface facing the sensor body 22: the other side surface of the present invention) of the gear portion 31. The center of the gear portion 31 is penetrated by the outer hole 39 and the shaft mounting hole 37.

The object 21 has a substantially disk shape of a thin plate with a center portion hollowed out, and includes: six radial members 40 extending in the radial direction; three inner circumferential members 41 extending in the circumferential direction and connecting the ends of the radial members 40 on the center side; and three outer circumferential members 42 extending in the circumferential direction and connecting outer ends of the radial members 40. The radial members 40, the inner circumferential member 41 and the outer circumferential member 42 each have a width and a thickness of about several mm. The radial members 40 are arranged at equal intervals in the circumferential direction, every other inner circumferential member 41 connects the center-side ends, and every other outer circumferential member 42 is circumferentially offset from the inner circumferential member 41 to connect the outer ends. The inner circumferential member 41 of the object 21 is provided with a claw 43 for positioning the object 21. The claw portions 43 are provided at circumferential intermediate positions of the outer peripheral side ends of the respective inner peripheral members 41, have widths and protruding lengths of about 1 to 2mm, and are vertically flexed with respect to the inner peripheral members 41.

The object 21 is disposed coaxially with the center of the gear portion 31 on the outer side surface of the gear portion 31 on the outer hole 39 side. The radially outer surface of the inner circumferential member 41 of the object 21 is substantially the same as the radial position of the edge of the outer hole 39 of the gear portion 31.

Grooves 45 for accommodating the outer circumferential member 42 and the radial member 40 are formed in the outer surface of the gear portion 31.

The lever member 33 is in the shape of a flat plate made of metal, and is buried inside the gear portion 31. The lever member 33 is provided with a circular center hole 50 at the center thereof, which is smaller than the outer diameter of the valve shaft 10. Further, a cylindrical protruding portion 51 protruding in the axial direction is included at one end of the valve shaft 10, and the protruding portion 51 is inserted into the center hole 50 of the lever member 33. The central hole 50 of the lever member 33 has a smaller diameter than the radially inner end surface of the inner circumferential member 41 of the object 21.

Further, three circular arc holes 52 (hole portions) extending in a circular arc shape are formed around the center hole 50 in the lever member 33. As shown in fig. 8 and 9, the three circular-arc holes 52 are substantially identical in shape and size to the inner circumferential member 41 of the object 21, and the three circular-arc holes 52 are arranged so as to coincide with substantially identical radial positions and circumferential positions to the inner circumferential member 41.

As shown in fig. 5, the gear portion 31, the lever member 33, and the object 21 are integrated by insert molding processing, and formed as a drive gear 15 as one component. The gear portion 31 is formed of resin with the metal rod member 33 and the object 21 as the insert. That is, at the point in time when the molding process of the gear portion 31 is completed, the lever member 33 and the object 21 have been combined.

As shown in fig. 6, the valve shaft 10 is fixed to the drive gear 15 including the lever member 33 and the object 21, and the valve shaft unit 30 is manufactured.

Specifically, as shown in fig. 7, one end of the valve shaft 10 is inserted into the shaft mounting hole 37 of the gear portion 31 of the drive gear 15, one end of the valve shaft 10 is brought into contact with the exposed portion 38 of the lever member 33 exposed from the shaft mounting hole 37, and the convex portion 51 of the valve shaft 10 is inserted into the center hole 50 of the lever member 33.

Then, as shown by arrows in fig. 7, the lever member 33 exposed to the outer hole 39 is irradiated with laser light from the outer side surface side of the drive gear 15 to weld the lever member 33 and the valve shaft 10. The laser light is preferably applied at three positions between the circular arc hole 52 and the center hole 50 of the stem member 33, where the laser light is applied to the back side of the contact surface between the stem member 33 and one end of the valve shaft 10.

Thereby, the valve shaft unit 30 having the drive gear 15 and the valve shaft 10 is manufactured, and the drive gear 15 includes the lever member 33 and the object 21.

As shown in fig. 10, when the drive gear 15 is formed by insert molding, the lever member 33 and the object 21 are supported by the gear molding dies 60 and 61.

The gear forming molds 60, 61 have: a cylindrical lower molding die 60, the shape of the lower molding die 60 being substantially the same as one end of the valve shaft 10; and a columnar upper molding die 61, wherein the lower surface of the upper molding die 61 is circular with a diameter larger than the outer shape of the inner circumferential member 41 of the object 21.

The lower molding die 60 has a cylindrical shape having substantially the same diameter as the shaft mounting hole 37 and capable of being inserted into the shaft mounting hole 37, and has a convex portion 62 having the same shape as the convex portion 51 of the valve shaft 10 formed on the upper surface thereof. The upper surface 60a of the lower molding die 60 includes a projection 63 having a cross-sectional shape substantially equal to that of the circular arc hole 52 of the rod member 33 and projecting upward. Three protruding portions 63 are provided with respect to the protruding portion 62 in alignment with the radial positions of the circular arc hole 52 with respect to the protruding portion 51 of the valve shaft 10. The upper surface 63a of the protruding portion 63 is parallel to the upper surface 60a of the lower molding die 60.

When the drive gear 15 is formed by insert molding, the lever member 33 is placed on the upper surface 60a of the lower molding die 60. At this time, the convex portion 62 of the lower molding die 60 is inserted into the center hole 50 of the lever member 33, and the protruding portion 63 of the lower molding die 60 is inserted into the circular arc hole 52 of the lever member 33. Further, the inner circumferential member 41 of the object 21 is placed on the upper surface 63a of the protruding portion 63 of the lower molding die 60. At this time, the outer surfaces of the three protruding portions 63 are provided so as to be sandwiched by the three claw portions 43 of the object 21.

The driving gear 15 including the lever member 33 and the object 21 is formed by filling resin in an inner space of a mold not shown provided so as to cover the upper molding mold 61 and the lower molding mold 60.

As described above, in the valve device 1 of the present embodiment, the drive gear 15 is fixed in order to transmit power from the electric motor 4 to the end portion of the valve shaft 10 to which the valve body 6 is fixed.

In the present embodiment, a metal rod member 33 is provided in the resin gear portion 31 of the drive gear 15 by insert molding. The gear portion 31 is provided with the object 21 of the induction sensor 20. The object 21 is also built in with the lever member 33 at the time of manufacturing the gear portion 31. Therefore, the drive gear 15 integrated with the lever member 33 and the object 21 is manufactured as a component.

The drive gear 15 having the lever member 33 and the object 21 is fixed to the end of the valve shaft 10 by laser welding, and the lever member 33 and the end of the drive gear 15 are fixed to the valve shaft 10.

Further, the lever member 33 is provided with a circular arc hole 52 extending in the circumferential direction radially outside of a welding position to be welded to the end of the valve shaft 10. Accordingly, when the stem member 33 and the valve shaft 10 are laser welded, welding heat is less likely to be transmitted from the radially inner welding portion of the circular arc hole 52 to the radially outer side. Therefore, at the time of laser welding of the lever member 33 and the valve shaft 10, heat is less likely to be transmitted to the gear portion 31 radially outside the circular arc hole 52, and thermal deformation of the gear portion 31 can be suppressed.

In addition, at the time of insert molding processing of the driving gear 15, the protruding portion 63 of the lower molding die 60 is inserted into the circular arc hole 52 of the lever member 33, and therefore, the lever member 33 is positioned with respect to the lower molding die 60. Thus, the drive gear 15 with accurate positioning of the lever member 33 in the drive gear 15 can be molded.

In addition, the protruding portion 63 of the lower molding die 60 inserted into the circular arc hole 52 from below during insert molding penetrates the rod member 33 and protrudes upward, and is a wall-shaped member that separates the radially outer side from the inner side above the rod member 33. Therefore, when the gear portion 31 is molded by insert molding, the resin can be restrained from winding into the radial inner side thereof by the protruding portion 63.

As a result, in the drive gear 15 after the insert molding process, the resin is not present so as to approach the inner side of the circular arc hole 52 of the lever member 33, and at the time of laser welding the lever member 33 and the valve shaft 10, the thermal influence on the resin portion can be suppressed, and the component quality of the drive gear 15 can be stabilized.

In addition, the tip of the protruding portion 63 of the lower molding die 60 inserted into the circular hole 52 is configured to hold the object to be inspected during the insert molding process. Therefore, the object 21 is also positioned with respect to the lower molding die 60 together with the lever member 33. This makes it possible to manufacture the high-quality drive gear 15 in which the object 21 is accurately positioned with respect to the gear portion 31 and the lever member 33.

Although the embodiments have been described above, the embodiment of the present invention is not limited to the above embodiments. For example, the detailed shapes of various members such as the shape of the gear portion 31 of the drive gear 15 may be changed as appropriate.

In the above embodiment, the present invention is applied to a throttle valve, but the present invention can be applied to various valve devices other than a throttle valve.

(symbol description)

1 a valve device;

6, a valve core;

10 valve shaft (shaft);

15 drive gears (gears);

20 induction sensor (non-contact sensor);

21 a subject;

30 valve shaft units;

33 bar members (support members);

37 shaft mounting holes (insertion holes);

38 an exposed portion;

39 outer holes (exposed holes);

52 circular arc holes (hole portions).

Claims (6)

1. A valve device, which is used for a valve,

the valve device comprises a resin plate-shaped gear at one end of a metal shaft for driving a valve element,

the valve device is characterized in that,

the gear has a metal support member integrated by insert molding in a state where at least a part is exposed at one side surface,

the exposed part of the supporting member in the gear is welded with the end part of the shaft to form a shaft unit,

the support member is provided with a hole extending in the circumferential direction radially outside a welding position where the support member is welded to the end portion of the shaft.

2. A valve device as claimed in claim 1, wherein,

the hole portion is a hole into which a protruding portion of a molding die of the gear is inserted so as to hold the support member at the time of the insert molding process.

3. A valve device as claimed in claim 2, wherein,

the protruding portion is inserted into the Kong Bushi groove, penetrates the support member, protrudes toward the front side in the insertion direction, and separates the radially outer side and the radially inner side of the protruding portion.

4. A valve device according to claim 3, wherein,

the other side surface side of the gear includes a detection object of a noncontact sensor that detects a rotation angle of the shaft, and the detection object is integrated with the gear together with the support member by the insert molding process.

5. The valve device of claim 4, wherein,

the protruding portion of the molding die penetrating the support member supports the object to be inspected during the insert molding process.

6. A valve device according to any one of claims 1 to 5,

the valve device is a throttle valve that controls the intake air amount of the internal combustion engine.