JP3361739B2 - Idle speed control valve - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an idle speed control valve suitable for use in controlling the idle speed of an internal combustion engine for automobiles.

[0002]

2. Description of the Related Art Generally, an engine for an automobile as an internal combustion engine is provided with an idle speed control valve in a throttle valve device for controlling an idle speed.

Therefore, a conventional throttle valve device having an idle speed control valve will be described with reference to FIGS. 4 to 7.

Reference numeral 1 is a throttle valve device arranged in the intake passage of the engine.
Is to open and close a throttle valve 9 described later by a rotation transmission mechanism 3 including a wire drum (not shown) connected to the wire 2.

Reference numeral 4 denotes a throttle body as a housing which forms the outer shape of the throttle valve device 1. The throttle body 4 is molded by aluminum die casting or the like, and the inside thereof is an intake air communicating with a cylinder (not shown) of the engine. A throttle chamber 5 serving as a passage is formed, and a throttle passage 4 and a control valve case 7 which will be described later are formed in the throttle body 4.

Reference numeral 6 is a bypass passage.
Is formed in the throttle body 4 so that one of the openings opens on the inflow side of the throttle chamber 5 and the other opens on the outflow side. Then, the bypass passage 6 is
The throttle chamber 5 is connected before and after the throttle valve 9, and the inflowing air is bypassed as shown by the arrow in FIG.

Reference numeral 7 is a control valve case constituting a part of the idle speed control valve 11 to which the idle speed control valve 11 is attached. The control valve case 7 faces the bypass passage 6 as shown in FIG. The control valve mounting hole 7A that is open, and the bypass passage 6 that communicates with the control valve mounting hole 7A
A large-diameter valve body accommodating chamber 7B that also serves as a valve seat, and a valve seat 7C that is located in the middle of the bypass passage 6 and on which a later-described valve body 15 accommodated in the valve body accommodating chamber 7B is seated. It is roughly composed of.

Reference numeral 8 denotes a valve shaft rotatably provided on the throttle body 4 by using a bearing (not shown). The valve shaft 8 is made of a high-strength metal rod or the like, and the throttle chamber 5 of the throttle body 4 is provided. It extends through the inside in the radial direction. Further, one side of the valve shaft 8 is connected to the wire 2 by using the rotation transmission mechanism 3, and the other end portion is connected to a throttle sensor 10 which will be described later.
Are linked to. Further, the valve shaft 8 is configured to open and close the throttle valve 9 integrated in the middle portion in the longitudinal direction.

Reference numeral 9 denotes a throttle valve rotatably provided in the throttle chamber 5 by a valve shaft 8. The throttle valve 9 is a disc-shaped valve plate, and its outer dimension is equal to the inner diameter dimension of the throttle chamber 5. It corresponds. The throttle valve 9 includes the rotation transmission mechanism 3 and the valve shaft 8.
Is rotated between a valve closed position and a valve open position, and the intake air amount of the engine is variably adjusted according to the opening degree.

Reference numeral 10 denotes a throttle sensor provided on the throttle body 4, and the throttle sensor 10 has a valve shaft 8
The rotation angle of the valve shaft 8 is connected to the other side and is detected as the opening of the throttle valve 9.

Reference numeral 11 denotes an idle speed control valve provided on the throttle body 4, and the idle speed control valve 1
1 includes a control valve case 7, a casing 12 and a stepping motor 13 which will be described later, and the like.

Reference numeral 12 denotes a stepped cylindrical casing attached to the control valve case 7. The casing 12 has a cylindrical portion 12A and a motor accommodating chamber 1 formed in the cylindrical portion 12A.
2B, a flange portion 12C formed on the tip end side of the cylindrical portion 12A, and a shaft insertion hole 12D located inside the flange portion 12C and penetrating the motor housing chamber 12B.
And an engaging groove 12E formed by axially cutting out a part of the shaft insertion hole 12D in the circumferential direction, and an annular spring accommodating groove 12F formed in the opening of the shaft insertion hole 12D. ing. The casing 12 is attached to the control valve case 7 by positioning the casing 12 on the control valve case 7 and screwing the flange portion 12C to the throttle body 4.

Reference numeral 13 denotes a motor housing chamber 12 of the casing 12.
The stepping motor 13 is housed in B. The stepping motor 13 rotates a screw shaft 14 serving as a rotating shaft by energizing the connector 13A protruding from the casing 12 from the outside.

Reference numeral 15 is a screw shaft 1 of the stepping motor 13.
4 is a valve body, and the valve body 15 is formed as a poppet valve body composed of a shaft portion 15A and a conical portion 15B. A screw hole 15C that meshes with the screw shaft 14 of the stepping motor 13 is formed in the shaft portion 15A of the valve body 15 in the axial direction, and an annular spring accommodating portion is formed between the shaft portion 15A and the conical portion 15B. The groove 15D is formed. Further, the engaging projection 1 extends in the axial direction in a part of the shaft portion 15A in the circumferential direction and is engaged with the engaging groove 12E of the casing 12.
5E is formed, and the engagement protrusion 15E is engaged with the engagement groove 12E of the casing 12, thereby restricting the rotation of the valve body 15 with respect to the casing 12.

Here, the screw shaft 14 of the stepping motor 13 and the valve body 15 which is prevented from rotating by the casing 12 constitute a screw feeding mechanism, and the screw feeding mechanism rotates the screw shaft 14 by the stepping motor 13. Due to
The valve body 15 is displaced in the axial direction.

Reference numeral 16 denotes a spring disposed between the spring accommodating groove 12F of the casing 12 and the spring accommodating groove 15D of the valve body 15, and the spring 16 is configured as a compression coil spring. And the spring 16
The spring force has a weak spring force that cancels backlash generated between the screw shaft 14 and the valve body 15 by urging the valve body 15 toward the valve closing side.

Reference numeral 17 denotes a water jacket formed on the throttle body 4. Cooling water for the engine is circulated through the water jackets through pipe lines 17A and 17A, and the cooling water causes the valve body 15 to move to the valve seat 7C. Prevents sticking due to freezing.

The idle speed control valve 11 described above rotates the screw shaft 14 in response to a control signal supplied from the outside to the stepping motor 13 during the idle operation of the engine for closing the throttle valve 9, and the valve body 15 is rotated. Control the axial displacement of. As a result, the idle speed control valve 11 is moved to the valve seat 7C of the bypass passage 6.
The flow passage area between the valve body 15 and the valve body 15 is variably controlled.

Thus, the idle speed control valve 11
Changes the flow passage area of the bypass passage 6 to variably control the flow rate of the auxiliary air supplied into the cylinder of the engine through the bypass passage 6, and adjusts the idle speed according to the load of the engine during idle operation. Have control. For example, even if the load on the engine is increased by operating the air conditioner or the like during idle operation of the engine, the idle speed control valve 11 increases the flow passage area of the bypass passage 6 by the valve body 15 so that It is possible to increase the amount of auxiliary air supplied and prevent engine stall.

[0020]

By the way, in the idle speed control valve 11 according to the above-mentioned prior art, in order to prevent backlash between the screw shaft 14 and the valve body 15, the valve body 15 and the casing 12 are prevented. A spring 16 is provided between And the spring 16
Has a spring force for urging the valve body 15 toward the valve seat 7C, this spring force must act in the opposite direction to the force for opening the valve body 15 by the stepping motor 13. become.

Therefore, as shown in FIG. 7, the idle speed control valve 11 according to the prior art is operated by the dirt attached to the valve body 15 when the valve body 15 is seated on the valve seat 7C and closed. The valve body 15 may stick to the seat 7C. In this case, when the valve body 15 is opened from the valve seat 7C,
Since the spring force of the spring 16 works in the direction of closing the valve, a large force is required for the stepping motor 13, and the idle speed control valve 11 according to the conventional technique drives the valve body 15 immediately after driving the stepping motor 13. Cannot be separated from the valve seat 7C, and there is a problem that responsiveness and reliability are deteriorated.

The present invention has been made in view of the above-mentioned problems of the prior art, and the present invention is capable of stably adjusting the amount of air flowing through the bypass passage and improving the responsiveness and reliability. Is intended to provide.

[0023]

In order to solve the above-mentioned problems, according to the invention of claim 1, a housing forming a bypass passage for bypassing an intake passage of an internal combustion engine, and a housing provided in the housing for conducting electricity. Between a stepping motor that rotates a screw shaft by means of a screw shaft and a valve seat that is provided on the screw shaft of the stepping motor so as to be displaceable only in the axial direction and that is formed in the bypass passage according to the rotation of the screw shaft. A valve body for changing the area, and provided on the valve body,
In an idle speed control valve comprising a spring that gives a spring force to the valve body that cancels backlash between the screw shaft of the stepping motor and the valve body, It is characterized in that it is configured to urge in the direction of separating from the seat.

With this structure, the spring force of the spring acts in the direction in which the valve element opens, so that the stepping motor opens the valve element even when the valve element is stuck to the valve seat of the bypass passage. The valve element can be easily opened by assisting the force in the direction.

According to the invention of claim 2, the spring is configured as a compression coil spring arranged between the valve body and the valve seat side of the housing.

According to the third aspect of the invention, the spring is constructed as a tension coil spring arranged between the valve body and the housing side of the stepping motor.

With this structure, the spring force of the spring acts in the direction of assisting the stepping motor, and the valve body can be easily separated from the valve seat.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an idle speed control valve according to the present invention will be described below in detail with reference to FIGS. In addition, in the present embodiment, the same components as those described in the above-mentioned related art are designated by the same reference numerals, and the description thereof will be omitted.

First, the idle speed control valve according to the first embodiment will be described with reference to FIGS.

Reference numeral 21 is an idle speed control valve according to the present embodiment. The idle speed control valve 21 includes a control valve case 22 and a stepping motor 24, which will be described later as a housing.

Reference numeral 22 is a control valve case forming a part of the idle speed control valve 21, and the control valve case 22 is formed in the throttle body 4 in place of the control valve case 7 described in the prior art. A control valve mounting hole 22A opened to face the bypass passage 6, and the control valve mounting hole 22A
And a valve body accommodating chamber 22B having a large diameter, which is formed in the valve body accommodating chamber 22B, which is located in the bypass passage 6 and is accommodated in the valve body accommodating chamber 22B. It is composed of a valve seat 22C to be seated and an annular spring accommodating groove 22D which is formed on the outer peripheral side of the valve seat 22C and accommodates a spring 27 described later.

Reference numeral 23 denotes a stepped cylindrical casing attached to the control valve case 22, and the casing 23 has a cylindrical portion 23A for accommodating a stepping motor 24 and the cylindrical portion 23A.
A flange portion 23B formed on the distal end side of the cylindrical portion 23A and a shaft insertion hole 2 which is located inside the flange portion 23B and through which the screw shaft 25 of the stepping motor 24 is inserted.
3C and the engagement groove 2 formed on the inner peripheral surface of the shaft insertion hole 23C, which is formed on the inner peripheral surface by cutting a part of the peripheral direction in the axial direction.
It is roughly composed of 3D. The casing 23 is mounted on the control valve case 22 by positioning the casing 23 on the control valve case 22 and screwing the flange portion 23B to the throttle body 4.

Reference numeral 24 denotes a stepping motor housed in a casing 23. The stepping motor 24 rotates a screw shaft 25 serving as a rotating shaft by supplying electric power to a connector 24A protruding from a base end side of the casing 23 from the outside. It is what makes me.

26 is a screw shaft 2 of the stepping motor 24.
5 is a valve body provided with the shaft body 26A,
It is formed as a poppet valve body composed of a conical portion 26B formed on the tip side of the shaft portion 26A and a flange portion 26C which is located at a large diameter portion of the conical portion 26B and has a diameter increased.
A screw hole 26D that meshes with the screw shaft 25 of the stepping motor 24 is axially formed in the shaft portion 26A of the valve body 26, and an annular spring accommodating groove 26E is formed on the conical portion 26B side of the collar portion 26C. Are formed. Further, an engaging protrusion 26F that extends in the axial direction and is engaged with the engaging groove 23D of the casing 23 is formed in a part of the circumferential direction of the shaft portion 26A, and the engaging protrusion 26F is engaged with the casing 23. Groove 2
By engaging with the 3D, the valve body 26 is moved to the casing 2
It regulates rotation with respect to 3.

Reference numeral 27 denotes a spring which functions as a compression coil spring, and the spring 27 is provided between the annular spring accommodating groove 26E of the valve body 26 and the spring accommodating groove 22D located on the valve seat 22C side of the control valve case 22. Is arranged,
The spring force of the spring 27 acts in the direction in which the valve body 26 opens. The spring force of the spring 27 has such a weak spring force as to cancel backlash generated between the screw shaft 25 and the valve body 26.

The idle speed control valve 21 according to this embodiment has the above-described structure, and the valve body 26 is rotated by the rotation of the screw shaft 25 by the stepping motor 24.
By moving the shaft in the axial direction, it is possible to increase or decrease the auxiliary air flowing through the bypass passage 6. As a result, the idle speed control valve 21 can prevent engine stall by increasing the amount of auxiliary air when the engine is idling and the load is applied.

However, in the present embodiment, the spring 27 serving as the compression coil spring is arranged between the valve body 26 and the control valve case 22 located on the valve seat 22C side. A spring 2 for urging the valve body 26 in the valve opening direction when the valve body 26 is displaced with respect to the valve seat 22C.
With the spring force of 7, the backlash generated between the screw shaft 25 and the valve body 26 can be suppressed.

Further, as shown in FIG. 2, the idle speed control valve 21 is operated when the valve body 26 is close to the closed state.
The spring force of the spring 27 acts in the direction in which the valve body 26 opens. Thereby, the spring 27 can assist the force in the direction of opening the valve body 26, and can reduce the load applied to the stepping motor 24 when the valve body 26 is displaced in the valve opening direction. Then, the stepping motor 24 can easily displace the valve body 26.

Further, even if the valve body 26 is seated on the valve seat 22C and closed, and the valve body 26 is fixed to the valve seat 22C due to dirt attached to the valve body 26, the backlash is removed. Since the spring force of the spring 27 acts in the direction in which the valve body 26 opens, the stepping motor 24
When the valve body 26 is opened by the valve seat 26,
It can be easily separated from 2C.

On the other hand, as shown in FIG. 1, when the valve body 26 is close to the fully open state, the spring force of the spring 27 is smaller than when the valve body 26 is in the valve closed state (see FIG. 2). Therefore, when the valve body 26 is closed by the stepping motor 24, the load due to the spring force of the spring 27 applied to the stepping motor 24 can be reduced.

Moreover, the idle speed control valve 21 according to the present embodiment can quickly react by the spring force of the spring 27 when shifting from the closed state to the open state, and stabilizes the amount of air flowing through the bypass passage 6. Can be adjusted. Then, it is possible to control the valve element 26 with good responsiveness when a load is applied to the engine during idle operation,
Prevents engine stall and idle speed control valve 2
The reliability of 1 can be improved.

Next, an idle speed control valve according to a second embodiment of the present invention will be described with reference to FIG. A feature of the present embodiment is that the spring is arranged between the valve body and the stepping motor side of the housing to form a tension coil spring. Further, in the present embodiment, the same components as those described in the first embodiment described above are designated by the same reference numerals, and the description thereof will be omitted.

Reference numeral 31 is an idle speed control valve according to this embodiment. The idle speed control valve 31 is a control valve case 32 and a casing 23 which will be a housing described later.
And a stepping motor 24 and the like.

Reference numeral 32 is a control valve case forming a part of the idle speed control valve 31, and the control valve case 32 is formed in the throttle body 4 in place of the control valve case 22 described in the first embodiment. Control valve mounting hole 32
A, a valve body accommodating chamber 32B, a valve seat 32C, an annular spring accommodating groove 32D, and the like.

33 is the screw shaft 2 of the stepping motor 24.
5, the valve body 33 is also formed as a poppet valve body including a shaft portion 33A, a conical portion 33B, and a collar portion 33C. The valve body 33 is formed with a screw hole 33D that meshes with the screw shaft 25 and an annular spring accommodation groove 33E. Further, an engagement protrusion 33F extending in the axial direction is formed on the shaft portion 33A, and the valve body 33 is attached to the casing 23.
It is regulated to rotate against.

Reference numeral 34 is a spring which functions as a tension coil spring, and one of the springs 34 has a valve body 33.
Is provided by fixing the other to a ring-shaped spring accommodation groove 33E and the other to a spring accommodation groove 32D located on the control valve mounting hole 32A (stepping motor 24) side of the control valve case 32, and the spring 34 is provided with a screw shaft. Two
The backlash between the valve 5 and the valve element 33 is canceled.

However, the idle speed control valve 31 according to the second embodiment is similar to the idle speed control valve 21 according to the first embodiment described above in that the spring 3 is used.
The spring force of 4 acts in the direction of opening the valve element 33. As a result, even when the valve element 33 is seated and fixed on the valve seat 32C, the stepping motor 24 is assisted by the spring force of the spring 34 acting in the valve opening direction of the valve element 33 to move the valve element 33. It can be opened easily.

The idle speed control valve according to the embodiment has been described as applied to the throttle valve device for rotating the valve shaft 8 by the rotation transmission mechanism 3 including a wire drum (not shown). The present invention is not limited to this, and may be applied to an electric throttle valve device that opens and closes the throttle valve 9 by an electric motor and a gear mechanism.

[0049]

As described in detail above, in the idle speed control valve according to the present invention, the valve body for changing the flow passage area of the bypass passage has a backlash generated between the screw shaft of the stepping motor and the valve body. Since a spring having a spring force that cancels the valve is provided and the spring force of the spring is biased in the direction in which the valve element opens, even when the valve element is fixed to the valve seat of the bypass passage, The spring force of the spring acts in the direction of assisting the stepping motor, the stepping motor can easily open the valve element, and the amount of air flowing through the bypass passage can be adjusted stably, and reliability is improved. Can be increased.

[Brief description of drawings]

FIG. 1 is a sectional view of essential parts showing an idle speed control valve according to a first embodiment.

FIG. 2 is a sectional view similar to FIG. 1, showing a state where the valve element of the idle speed control valve according to the first embodiment is closed.

FIG. 3 is a cross-sectional view of essential parts showing an idle speed control valve according to a second embodiment.

FIG. 4 is a plan view showing a throttle valve device provided with an idle speed control valve according to the prior art.

5 is a vertical cross-sectional view showing an idle speed control valve, a bypass passage and the like as seen from the direction of arrow VV in FIG.

FIG. 6 is a sectional view of an essential part showing an idle speed control valve according to a conventional technique.

FIG. 7 is a sectional view similar to FIG. 6, showing a state in which a valve element of an idle speed control valve according to a conventional technique is closed.

[Explanation of symbols]

6 bypass passage 21,31 Idle speed control valve 22, 32 Control valve case (housing) 22C, 33C valve seat 22D, 26E, 32D, 33E Spring accommodation groove 23 casing 24 stepping motor 25 screw shaft 26,33 valve body 27, 34 springs

Claims (3)

(57) [Claims] 1. A housing having a bypass passage for bypassing an intake passage of an internal combustion engine, a stepping motor provided in the housing for rotating a screw shaft by energizing, and an axial direction of the screw shaft of the stepping motor only. A valve body that is displaceable and that changes a flow passage area between the valve shaft and a valve seat formed in the bypass passage according to rotation of the screw shaft; and a screw shaft of the stepping motor that is provided in the valve body. In an idle speed control valve including a spring that applies a spring force to the valve body such that the backlash between the valve body and the valve body is cancelled, the spring is attached in a direction that separates the valve body from the valve seat. Idle speed control valve characterized by being configured to energize. 2. The idle speed control valve according to claim 1, wherein the spring is configured as a compression coil spring arranged between the valve body and a valve seat side of the housing. 3. The idle speed control valve according to claim 1, wherein the spring is configured as a tension coil spring arranged between the valve body and a stepping motor side of the housing.