JP2013238126A - Valve drive unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic throttle device, in which a seal member 18 is easily attached, and assemblability of a sensor cover 5 can be improved, while reliable sealing performance can be secured by preventing coming-off of the seal member 18.SOLUTION: Four corner pins 19 for mounting a seal member 18 are erected on a sensor cover 5. The seal member 18 is an annular rubber product having a rectangular cross-sectional shape and bridged with tensile force to four corner pins 19. After the seal member 18 is mounted in four corner pins 19, the sensor cover 5 is assembled to one end surface of a throttle body 3 having a gear chamber formed therein and fastened to be fixed to the throttle body 3 with a screw or the like. Thus, the gear chamber of throttle body 3 is airtightly closed by the sensor cover 5 through compression deformation by pressing the seal member 18 onto a gap between a body side sealing surface Sb and cover side sealing surface Sc.

Description

  The present invention relates to a valve drive unit that controls the flow rate of intake air or exhaust gas of an internal combustion engine, and more particularly, to a seal structure for ensuring airtightness between a body body and a sensor cover.

As a prior art, an electronic throttle device disclosed in Patent Document 1 is known.
In this electronic throttle device, as shown in FIG. 30, a sensor cover 120 is assembled to the end surface of the throttle body 100 via a rubber seal member 110, and the sensor cover 120 is fixed to the throttle body 100 by screws or the like. .
The seal member 110 is fitted in and attached to a seal groove 130 (see FIG. 31) having a concave cross section formed on the entire circumference of the sensor cover 120, and the seal member 110 is fixed when the sensor cover 120 is fixed to the throttle body 100. Is pressed against the end face of the throttle body 100, so that the space between the throttle body 100 and the sensor cover 120 is hermetically sealed.

JP 2004-144039 A

  However, in the seal structure of Patent Document 1, it is extremely difficult to fit the seal member 110 into the seal groove 130 having a narrow groove width. That is, since the seal member 110 is an annular product without a terminal and is flexible to such an extent that it cannot be retained by itself, it is impossible to fit the seal member 110 into the entire circumference of the seal groove 130 at once. It is necessary to install it while pushing it into the seal groove 130 little by little. Further, the entire circumferential shape of the seal groove 130 is not a simple rectangular shape, but an intermediate portion of the seal groove 130 extending in the longitudinal direction (the vertical direction in the drawing) of the sensor cover 120 is a sensor cover 120 as shown in part A of FIG. Since it is depressed toward the center of the seal member 110, it is difficult to assemble the seal member 110.

  Further, if there is a depression as shown in the above-mentioned part A in the middle of the seal groove 130, the seal member 110 is biased toward one side of the seal groove 130, so that there is a gap between the seal member 110 and the seal groove 130. The part which becomes large arises. For this reason, when the sensor cover 120 is assembled to the throttle body 100, the seal member 110 may partially drop from the seal groove 130. As a result, not only is it difficult to fit the seal member 110 into the seal groove 130, but it is also difficult to assemble the sensor cover 120 to the throttle body 100 so that the fitted seal member 110 does not fall out of the seal groove 130. is there.

Further, if the sensor cover 120 is assembled to the throttle body 100 with the seal member 110 partially removed from the seal groove 130, the seal member 110 is bitten between the end surfaces of the throttle body 100 and the sensor cover 120. Needless to say, a reliable sealing function cannot be ensured and airtightness is impaired.
The present invention has been made based on the above circumstances, and its purpose is to ensure a reliable sealing function by eliminating the dropping of the sealing member, and to easily attach the sealing member, and Another object of the present invention is to provide a valve drive unit that can improve the assembling property of the sensor cover.

  The present invention according to claim 1 is a body body forming a part of a passage of an intake system or an exhaust system of an internal combustion engine, a valve for adjusting a flow rate of intake air or exhaust gas of the internal combustion engine flowing through the passage, A motor that generates a rotational force upon receiving electric power, a power transmission means that transmits the rotational force generated in the motor to the valve, a valve opening sensor that detects the opening of the valve, and the valve opening sensor A sensor cover that is held and fixed to one end surface of the body main body, and a gear chamber that houses the power transmission means is recessed in the one end surface of the body main body, and the opening of the gear chamber is made of an elastic body. A valve drive unit that is closed by a sensor cover via an annular seal member, and a plurality of guide members that support the seal member are directed to the other side of either the sensor cover or the body body. The seal member is stretched over a plurality of guide members with tension, and is pressed between the seal surface on the body side and the seal surface on the sensor cover side when the sensor cover is assembled to the body body. It is retained.

  According to the above seal structure, since the seal member is attached to the plurality of guide members with tension, the seal member does not easily fall off when the sensor cover is assembled to the body body. Further, when the seal member is attached, it is not necessary to fit the seal member into the seal groove having a narrow groove width as in the prior art disclosed in Patent Document 1, and the plurality of guide members are hooked with tension. Therefore, it is easy to mount the seal member. Furthermore, when the sensor cover is assembled to the body body, the seal member does not easily fall off, so that the assemblability of the sensor cover is improved. In addition, a guide member can also be provided in a sensor cover and can also be provided in a body main body.

As described in the invention of claim 2, the guide member can be a rod-shaped corner pin or a corner guide that is curved in an arc shape. Alternatively, a corner pin and a corner guide can be used in combination.
Furthermore, as described in the invention of claim 3, when the sensor cover is assembled to the body body, the corner pin can use a positioning pin for positioning the sensor cover. In this case, a positioning hole that fits the positioning pin is formed on the other of the sensor cover and the body body, that is, on the side where the corner pin is not provided.

It is sectional drawing of an electronic throttle device. (Example 1) which is the II-II arrow line view of FIG. 1 which looked at the sensor cover from the inside. FIG. 3 is a sectional view taken along line III-III in FIG. 2 (Example 1). (A) IV-IV sectional drawing of FIG. 2, (b) IV-IV sectional drawing of FIG. 2 (Example 1). (A) It is sectional drawing which shows the process of assembling a sensor cover to a throttle body, (b) It is sectional drawing which shows the state which assembled | attached both (Example 1). FIG. 3 is a cross-sectional view corresponding to the III-III cross section of FIG. 2 (Example 2). (A) Cross-sectional view corresponding to the IV-IV cross section of FIG. 2, (b) Cross-sectional view corresponding to the IV-IV cross section of FIG. 2 (Example 2). (A) It is sectional drawing which shows the process of assembling a sensor cover to a throttle body, (b) It is sectional drawing which shows the state which assembled | attached both (Example 2). (A) It is sectional drawing which shows the process of assembling a sensor cover to a throttle body, (b) It is sectional drawing which shows the state which assembled | attached both (Example 3). FIG. 3 is a cross-sectional view corresponding to the III-III cross section of FIG. 2 (Example 4). (A) Cross-sectional view corresponding to the IV-IV cross section of FIG. 2, (b) Cross-sectional view corresponding to the IV-IV cross section of FIG. 2 (Example 4). (A) It is sectional drawing which shows the process of assembling a sensor cover to a throttle body, (b) It is sectional drawing which shows the state which assembled | attached both (Example 4). FIG. 3 is a cross-sectional view corresponding to the III-III cross section of FIG. 2 (Example 4). (A) Cross-sectional view corresponding to the IV-IV cross section of FIG. 2, (b) Cross-sectional view corresponding to the IV-IV cross section of FIG. 2 (Example 4). (A) It is sectional drawing which shows the process of assembling a sensor cover to a throttle body, (b) It is sectional drawing which shows the state which assembled | attached both (Example 4). (A) It is sectional drawing which shows the process of assembling a sensor cover to a throttle body, (b) It is sectional drawing which shows the state which assembled | attached both (Example 4). (Example 5) which is a top view of arrangement example (a)-(e) of a corner pin. (Example 6) which is a top view which shows the example which uses a corner guide. (Example 6) which is a top view which shows the example which uses a corner guide. (Example 7) which is a top view which shows the example which combined the corner pin and the corner guide. (Example 7) which is a top view which shows the example which combined the corner pin and the corner guide. (A) It is sectional drawing which shows the state which assembled | attached the sensor cover to the throttle body, (b) It is sectional drawing of the sensor cover of the part which erected the corner pin (Example 7). (A) It is sectional drawing which shows the state which assembled | attached the sensor cover to the throttle body, (b) It is sectional drawing of the throttle body of the part which erected the corner pin (Example 7). (A) Sectional drawing equivalent to the III-III cross section of FIG. 2, (b) It is sectional drawing which shows the state which assembled | attached the sensor cover to the throttle body (Example 8). (A) Sectional drawing equivalent to the III-III cross section of FIG. 2, (b) It is sectional drawing which shows the state which assembled | attached the sensor cover to the throttle body (Example 8). (Example 8) which is sectional drawing which formed the taper surface in the sealing surface of a sensor cover. (A) Sectional drawing equivalent to the III-III cross section of FIG. 2, (b) It is sectional drawing which shows the state which assembled | attached the sensor cover to the throttle body (Example 8). (A) Sectional drawing equivalent to the III-III cross section of FIG. 2, (b) It is sectional drawing which shows the state which assembled | attached the sensor cover to the throttle body (Example 8). (Example 8) which is sectional drawing which formed the taper surface in the sealing surface of a sensor cover. It is sectional drawing which shows the seal structure which concerns on a prior art. It is the top view which looked at the sensor cover which concerns on a prior art from the inner side.

  The mode for carrying out the present invention will be described in detail with reference to the following examples.

Example 1
In the first embodiment, an example in which the valve drive unit of the present invention is applied to an electronic throttle device for controlling the intake air amount of an engine will be described.
As shown in FIG. 1, the electronic throttle device 1 includes a throttle body 3 having a built-in throttle valve 2 for adjusting the amount of intake air taken in by an engine (not shown), and valve driving means for driving the throttle valve 2 to rotate. (Described later), a throttle opening sensor 4 that detects the opening of the throttle valve 2, a sensor cover 5 that holds the throttle opening sensor 4 and is fixed to the throttle body 3, and the like.
The throttle body 3 is made of, for example, aluminum die casting, and forms an intake passage 6 having a circular cross section through which intake air flows. The air upstream side of the intake passage 6 is connected to an air cleaner (not shown) via an air hose or the like, and the air downstream side is connected to an intake manifold or a surge tank (both not shown).

The throttle valve 2 is a butterfly valve that includes a disc-shaped valve body 2a and a valve shaft 2b that forms a rotation shaft of the valve body 2a, and the valve shaft 2b is disposed at the center of the valve body 2a.
For example, the valve body 2 a is assembled by being inserted into a slit formed in the valve shaft 2 b, and is fastened and fixed to the valve shaft 2 b by a screw 7.
The valve shaft 2b is disposed so as to pass through the intake passage 6 formed in the throttle body 3 in the radial direction, and one end in the axial direction is supported by the throttle body 3 via the metal bearing 8, and the other end is It is supported on the throttle body 3 via a ball bearing 9.

The valve driving means includes a motor 10 that generates a rotational force when supplied with electric power, and a gear reduction device 11 (described below) that transmits the rotational force of the motor 10 to the valve shaft 2b. The motor 10 is, for example, a known DC motor, and is controlled by an ECU (not shown) via a motor drive circuit (not shown). The motor 10 is stored in a motor storage chamber 3 a formed in the throttle body 3.
The ECU is an electronic control device that controls the throttle opening in accordance with the driver's accelerator operation, and a target throttle opening based on an output signal of an accelerator opening sensor (not shown) that detects the amount of depression of the accelerator pedal. And the power supplied to the motor 10 is feedback-controlled so that the opening degree of the throttle valve 2 detected by the throttle opening degree sensor 4 matches the target throttle opening degree.

The gear reduction device 11 includes a pinion gear 12 formed on the output shaft 10 a of the motor 10, a valve gear 13 attached to the valve shaft 2 b, and an intermediate gear that transmits the rotation of the pinion gear 12 to the valve gear 13. The intermediate gear has a large-diameter gear 14 that meshes with the pinion gear 12 and a small-diameter gear 15 that meshes with the valve gear 13, and the large-diameter gear 14 and the small-diameter gear 15 are integrally provided on the same axis, 15 is rotatably supported on a common intermediate shaft 16. The gear reduction device 11 is housed in a gear chamber 3 b that opens at one end surface of the throttle body 3 and is covered by the sensor cover 5.
The throttle opening sensor 4 is, for example, a non-contact type position sensor using two Hall ICs, and detects the position of the permanent magnet 17 attached to the valve shaft 2b to generate a magnetic field generated by the permanent magnet 17. An electric signal proportional to the magnitude of the output is output to the ECU.

The sensor cover 5 is a resin molded product, and is assembled to one end face of the throttle body 3 forming the gear chamber 3b via a seal member 18, and is fastened and fixed to the throttle body 3 by screws or the like.
Next, the seal structure of the electronic throttle device 1 will be described in detail.
In the following description, the pressing surface on the throttle body 3 side that presses the seal member 18 between the sensor cover 5 and the throttle body 3 is referred to as a body side sealing surface Sb, and the pressing surface on the sensor cover 5 side is the cover side sealing surface. Called Sc (see FIG. 5).

As shown in FIG. 2, the sensor cover 5 is provided with four corner pins 19 for attaching the seal member 18, one for each corner of the sensor cover 5. The corner pin 19 is also a positioning pin for positioning the sensor cover 5 when the sensor cover 5 is assembled to the throttle body 3. In other words, the positioning pin is used as the corner pin 19. Accordingly, as shown in FIG. 5, a positioning hole 20 facing the corner pin 19 (positioning pin) is recessed in one end surface of the throttle body 3 to which the sensor cover 5 is assembled, and the sensor cover 5 is assembled to the throttle body 3. The tip of the corner pin 19 is fitted into the positioning hole 20.
The seal member 18 is, for example, a rubber annular product having a rectangular cross-sectional shape, and the longitudinal direction of the rectangular cross-section is arranged along the upright direction (vertical direction in the drawing) of the corner pin 19 as shown in FIG. As shown in FIG. 2, the four corner pins 19 are wound around with tension.

  Between the adjacent corner pins 19 and the corner pins 19, as shown in FIG. 4, an inner wall portion 21 is erected along the inner peripheral edge of the cover-side seal surface Sc. The inner wall 21 supports the inner peripheral side surface of the seal member 18 that is stretched over the four corner pins 19. However, the inner wall portion 21 is set to be lower than the corner pin 19. That is, the height of the inner wall portion 21 is formed to be low enough not to interfere with the throttle body 3 in a state where the tip of the corner pin 19 that is also a positioning pin is fitted in the positioning hole 20. Therefore, the height of the inner wall portion 21 can be arbitrarily set as long as it does not interfere with the throttle body 3. In the example of FIG. 4A, the height of the inner wall portion 21 is formed smaller (lower) than the dimension in the longitudinal direction of the seal member 18. For example, as shown in FIG. The height of the inner wall portion 21 can be made larger (higher) than the dimension in the longitudinal direction of 18.

  On the other hand, as shown in FIG. 5, an outer wall portion 22 is erected on the throttle body 3 on the entire outer circumference side of the body-side seal surface Sb. The outer wall portion 22 is disposed on the outer peripheral side of the seal member 18 to protect the outer peripheral side surface of the seal member 18 when the sensor cover 5 to which the seal member 18 is attached is assembled to the throttle body 3. The outer wall 22 is set to a height that does not interfere with the sensor cover 5, but if the height of the outer wall 22 is too low compared to the longitudinal dimension of the seal member 18, A gap generated between the front end surface and the opposing surface on the sensor cover 5 side is increased. As a result, the outer peripheral side surface of the seal member 18 is greatly exposed to the outside, so that the effect of protecting the outer peripheral side surface of the seal member 18 is reduced.

  Therefore, from the viewpoint of protecting the outer peripheral side surface of the seal member 18, it is desirable to increase the height of the outer wall portion 22 within a range that does not interfere with the sensor cover 5. In other words, it is better that the gap generated between the front end surface of the outer wall portion 22 and the opposing surface on the sensor cover 5 side is reduced. However, it is not always necessary to provide a gap between the front end surface of the outer wall portion 22 and the opposing surface on the sensor cover 5 side, and a tightening margin required for the seal member 18 in a state where the sensor cover 5 is fixed to the throttle body 3. Is obtained, the front end surface of the outer wall portion 22 may abut against the opposing surface on the sensor cover 5 side.

The sensor cover 5 is assembled to the throttle body 3 in the direction indicated by the arrow as shown in FIG. 5A with the seal member 18 attached to the four corner pins 19 with tension. At this time, the tip of the corner pin 19 that is also a positioning pin is fitted into the positioning hole 20 formed in the throttle body 3, thereby preventing the sensor cover 5 from being displaced with respect to the throttle body 3. As a function of the electronic throttle device 1, the positional relationship between the throttle opening sensor 4 and the permanent magnet 17 can be maintained appropriately.
Thereafter, the sensor cover 5 is fastened and fixed to the throttle body 3 with a screw or the like, whereby the fixing force is applied to the seal member 18. That is, the seal member 18 is compressed between the body side seal surface Sb and the cover side seal surface Sc as shown by an arrow in FIG. As a result, the gear chamber 3 b formed in the throttle body 3 is airtightly covered by the sensor cover 5 via the seal member 18.

(Operation and Effect of Example 1)
According to the above-described seal structure, since the seal member 18 is attached to the four corner pins 19 with tension, the seal member 18 is easily detached from the sensor cover 5 when the sensor cover 5 is assembled to the throttle body 3. There is nothing.
Further, when attaching the seal member 18 to the sensor cover 5, it is not necessary to fit the seal member 18 into the seal groove having a narrow groove width as in Patent Document 1, and the four corner pins 19 have tension. Since it only needs to be hooked, it is extremely easy to attach the seal member 18 to the sensor cover 5 as compared with Patent Document 1.
Further, when the sensor cover 5 is assembled to the throttle body 3, the seal member 18 does not easily fall off, so that the assembling property of the sensor cover 5 is also improved.

In the seal structure disclosed in Patent Document 1, for example, when the seal member 18 having a rectangular cross section is used as in the first embodiment, the seal member 18 may be fitted in the seal groove in a twisted state. In this case, since it is necessary to remove the seal member 18 from the seal groove and correct the twist, it is necessary to fit the seal member 18 into the seal groove again. Need. On the other hand, in the seal structure described in the first embodiment, even when the seal member 18 is attached to the four corner pins 19 in a twisted state, the seal member 18 is not inserted into the seal groove. The twist of the seal member 18 can be easily corrected. Therefore, compared with the seal structure disclosed in Patent Document 1, the attaching operation of the seal member 18 can be performed easily and in a short time.
In the seal structure described in the first embodiment, since the positioning pin is used as the corner pin 19, it is not necessary to newly provide the corner pin 19. However, it is not denied that the corner pin 19 is provided separately from the positioning pin.

Subsequently, another embodiment according to the present invention will be described.
In addition, also in Example 2-Example 8 described below, the same code | symbol is attached | subjected to the structure and components same as Example 1. FIG.
(Example 2)
In the first embodiment, the configuration in which the outer wall portion 22 that protects the outer peripheral side surface of the seal member 18 is provided in the throttle body 3 has been described. However, in the second embodiment, as shown in FIG. This is an example in which an outer wall portion 22 is provided.
In this case, the outer wall portion 22 is set to a height that does not interfere with the throttle body 3 when the sensor cover 5 is assembled to the throttle body 3. That is, it is set lower than the height of the corner pin 19. When the outer wall portion 22 is provided on the sensor cover 5, as shown in FIGS. 6 and 7, between the corner pin 19 and the outer wall portion 22 and between the inner wall portion 21 and the outer wall portion 22. Although the concave groove is formed, the seal member 18 does not need to be in contact with the bottom surface of the concave groove, that is, the cover-side seal surface Sc before the sensor cover 5 is assembled to the throttle body 3.

Therefore, as shown in FIG. 8A, the seal member 18 is hooked on the tip end side of the corner pin 19, in other words, the seal member 18 is mounted in a state of floating from the bottom surface of the concave groove (the cover-side seal surface Sc). When the sensor cover 5 is assembled to the throttle body 3, the seal member 18 is pushed into the concave groove by the body-side seal surface Sb of the throttle body 3 as shown in FIG. The member 18 can be assembled.
7 is a cross-sectional view corresponding to the IV-IV cross section of FIG. 2, and FIG. 7A shows a case where the height of the inner wall portion 21 is smaller (lower) than the longitudinal dimension of the seal member 18. FIG. 5B shows an example in which the height of the inner wall portion 21 is larger (higher) than the longitudinal dimension of the seal member 18.

(Example 3)
The third embodiment is an example in which outer wall portions 22 are provided on both the sensor cover 5 and the throttle body 3 as shown in FIG. In this configuration, as shown in FIG. 9B, when the sensor cover 5 is assembled to the throttle body 3, the seal member 18 is pressed and held between the cover-side seal surface Sc and the body-side seal surface Sb. That is, in a state where the necessary tightening allowance is given to the seal member 18, the end surfaces of the outer wall portion 22 on the cover side and the outer wall portion 22 on the body side come into contact with each other, so that the outer peripheral side surface of the seal member 18 is Can be protected. Note that the end surfaces of the cover-side outer wall portion 22 and the body-side outer wall portion 22 do not necessarily have to contact each other, and a configuration in which a slight gap is generated between them may be employed.
In the configuration of the third embodiment, even if the sensor cover 5 is provided with the outer wall portion 22, the height can be lowered. Therefore, when the seal member 18 is attached to the four corner pins 19, the outer wall portion 22 is greatly disturbed. The seal member 18 can be easily attached to the corner pin 19.

Example 4
In the first to third embodiments, the configuration in which the corner pin 19 is provided on the sensor cover 5 is described. However, the fourth embodiment is an example in which the corner pin 19 is provided on the throttle body 3. 15. As shown in FIG. 16, a positioning hole 20 that faces the corner pin 19 is formed.
Even when the corner pin 19 is erected on the throttle body 3, the method of attaching the seal member 18 is the same as that of the first embodiment, that is, the seal member 18 only needs to be hooked on the four corner pins 19, so the same as in the first embodiment. An effect can be obtained.
10 to 12 are examples corresponding to the configuration of the first embodiment, FIGS. 13 to 15 are examples corresponding to the configuration of the second embodiment, and FIG. 16 is a case corresponding to the configuration of the third embodiment. is there.

(Example 5)
The fifth embodiment is an example in which the arrangement of the corner pins 19 is changed.
For example, as shown in FIGS. 17A to 17E, the arrangement of the corner pins 19 can be appropriately changed according to the mounting shape of the seal member 18.
Further, the corner pin 19 is provided not only at the inner peripheral side of the seal member 18 but also at a position for supporting the outer peripheral side of the seal member 18 as shown in FIGS. 17 (c), 17 (d) and 17 (e). You can also. In the case shown in FIGS. 17C to 17E, the corner pin 19 that supports the outer peripheral side of the seal member 18 is marked with a symbol (out).
Since the corner pin 19 only needs to be arranged so that tension is applied to the seal member 18, the corner pin 19 can flexibly cope with the mounting shape of the seal member 18 as shown in FIGS. In other words, by appropriately changing the arrangement of the corner pins 19, the mounting shape of the seal member 18 can be varied, and various cover shapes can be realized accordingly.

(Example 6)
The sixth embodiment is an example in which a corner guide 23 curved in an arc shape is used instead of the corner pin 19 described in the first to fifth embodiments.
18 is an example in which corner guides 23 are provided for each corner (four locations) of the sensor cover 5, and FIG. 19 is a corner guide having a smaller curvature (a larger radius of curvature) than the corner guide 23 used in FIG. 23 is an example provided at two locations facing the longitudinal direction (the vertical direction in the figure) of the sensor cover 5.
When the corner pin 19 is used, as shown in FIG. 2, it is effective when the mounting shape of the seal member 18 is square, but when the mounting shape of the seal member 18 is oval, in other words, it is square. If not, the corner guide 23 is more suitable than the corner pin 19.

Even when the corner guide 23 is used, the method of attaching the seal member 18 is the same as that of the corner pin 19. That is, in the example of FIG. 18, the seal member 18 is stretched over four corner guides 23 with tension. By assembling the sensor cover 5 with the seal member 18 attached to the corner guide 23 to the throttle body 3 and tightening and fixing with a screw or the like, the same sealing function as in the first embodiment can be realized.
In the above description, the corner guide 23 is provided on the sensor cover 5, but it can also be provided on the throttle body 3 as in the case of the corner pin 19.

(Example 7)
The seventh embodiment is an example in which the corner pin 19 and the corner guide 23 are used in combination. In the case where an angular portion and an arc-curved portion are mixed in the mounting shape of the seal member 18, for example, as shown in FIGS. 20 and 21, a corner pin 19 and a corner guide 23 may be used in combination. It is valid.
As described in the first embodiment, when the positioning pin is used as the corner pin 19, the corner guide 23 does not interfere with the throttle body 3 or the sensor cover 5 when the sensor cover 5 is assembled to the throttle body 3. The height of the corner guide 23 is set lower than the height of the corner pin 19 (see FIGS. 22 and 23). FIG. 22 shows an example in which the corner pin 19 and the corner guide 23 are provided on the sensor cover 5, and FIG. 23 shows an example in which the corner pin 19 and the corner guide 23 are provided on the throttle body 3.

  When the corner pin 19 and the corner guide 23 are provided on the sensor cover 5, as shown in FIG. 22A, a seal member is provided between the inner corner wall 24 facing the corner guide 23 and the inner corner wall 24. An outer corner wall 26 forming 18 mounting grooves 25 is erected on the throttle body 3. On the other hand, when the corner pin 19 and the corner guide 23 are provided on the throttle body 3, as shown in FIG. 23A, a seal member is provided between the inner corner wall 24 facing the corner guide 23 and the inner corner wall 24. An outer corner wall 26 forming 18 mounting grooves 25 is erected on the sensor cover 5. Thereby, even if the height of the corner guide 23 is set lower than the height of the corner pin 19, the seal member 18 exceeds the corner guide 23 due to the contact between the end surfaces of the corner guide 23 and the opposite inner corner wall 24. Can be prevented from protruding to the inner peripheral side. The outer corner wall 26 also serves to protect the outer peripheral side surface of the seal member 18 in the same manner as the outer wall portion 22 described in the first embodiment.

(Example 8)
In the first embodiment, the sealing member 18 having a rectangular cross section is used. However, the sealing member 18 is not limited to a rectangular cross section, and any sealing member 18 may be used as long as the sealing member 18 can be pushed along the corner pin 19. good.
In Example 8, examples of circular cross sections that can be assumed other than rectangular cross sections are shown in FIGS. 24 to 26, and examples of elliptic cross sections are shown in FIGS.
When the sealing member 18 having a circular cross section and an elliptical cross section is used, as shown in FIGS. 24B, 25B, 27B, and 28B, the body-side sealing surface Sb and the cover are covered. When the seal member 18 is pressed between the side seal surface Sc in the up and down arrow direction in the figure, the seal member 18 is compressed and deformed and swells in the left and right direction in the figure, and therefore between the corner pin 19 and the outer wall portion 22 and A sub-pressing force that presses the seal member 18 in the left and right arrow directions shown in the drawing acts between the inner wall portion 21 and the outer wall portion 22. As a result, the contact surface with which the seal member 18 comes into contact increases, in other words, the press surface that presses the seal member 18 increases, so that airtightness is improved.

Further, when the seal member 18 having a circular cross section and an elliptic cross section is used, a tapered surface 27 that presses the seal member 18 may be provided on either the body side seal surface Sb or the cover side seal surface Sc.
For example, when the corner pin 19 is erected on the sensor cover 5, as shown in FIGS. 26 and 29, the tapered surface 27 can be formed on the body-side seal surface Sb, and the corner pin 19 is erected on the throttle body 3. In this case, the tapered surface 27 can be formed on the cover-side seal surface Sc. In this case, since the pressing force that presses the seal member 18 also acts on the tapered surface 27, the pressing surface that presses the seal member 18 increases, and the airtightness is further improved.
24 to 29 show an example in which the corner pin 19 is provided on the sensor cover 5, it goes without saying that the configuration of the eighth embodiment can be applied even when the corner pin 19 is provided on the throttle body 3.

(Modification)
In the first embodiment, an example in which the valve drive unit of the present invention is applied to the electronic throttle device 1 has been described. However, in addition to the electronic throttle device 1, for example, a part of exhaust gas discharged from the engine is recirculated to the intake system. The seal structure of the present invention can also be applied to an EGR device that circulates or an intake throttle device that generates intake negative pressure in an intake system passage of an engine.

1 Electronic throttle device (valve drive unit)
2 Throttle valve (valve)
3 Throttle body (body body)
4 Throttle opening sensor (valve opening sensor)
5 Sensor cover 6 Air intake passage (passage)
10 motor 11 gear reduction device (power transmission means)
18 Sealing member 19 Corner pin (guide member)
23 Corner guide (guide member)
Sb Body side sealing surface Sc Cover side sealing surface

Claims (7)

A body body (3) forming part of a passage (6) of an intake system or an exhaust system of the internal combustion engine;
A valve (2) for adjusting the flow rate of intake air or exhaust gas of the internal combustion engine flowing through the passage (6);
A motor (10) that receives a supply of electric power and generates a rotational force;
Power transmission means (11) for transmitting the rotational force generated in the motor (10) to the valve (2);
A valve opening sensor (4) for detecting the opening of the valve (2);
A sensor cover (5) that holds the valve opening sensor (4) and is fixed to one end surface of the body body (3);
A gear chamber (3b) for accommodating the power transmission means (11) is recessed in one end surface of the body body (3), and an opening of the gear chamber (3b) is an annular seal that is an elastic body. A valve drive unit (1) closed by the sensor cover (5) via a member (18),
In either one of the sensor cover (5) and the body body (3), a plurality of guide members (19, 23) supporting the seal member (18) are erected toward the other side,
The seal member (18) is stretched over the plurality of guide members (19, 23) with tension. When the sensor cover (5) is assembled to the body body (3), the body body ( 3) A valve drive unit which is pressed and held between a seal surface (Sb) on the side and a seal surface (Sc) on the sensor cover (5) side. In the valve drive unit (1) according to claim 1,
The guide member (19, 23) is a rod-shaped corner pin (19) or a corner guide (23) curved in an arc shape, or the corner pin (19) and the corner guide (23) are connected to each other. A valve drive unit characterized by being used in combination. In the valve drive unit (1) according to claim 2,
The corner pin (19) is a positioning pin for positioning both the sensor cover (5) and the body main body (3) when the sensor cover (5) is assembled to the body main body (3). One of the other is formed with a positioning hole (20) that fits into the positioning pin. In any one valve drive unit (1) as described in Claims 1-3,
The sensor cover (5) or the body main body (3) on which the guide member (19, 23) is erected has an inner periphery of the seal member (18) attached to the guide member (19, 23). A valve drive unit characterized in that an inner wall (21) supporting the side is erected toward the other side. In the valve drive unit (1) according to claim 3,
When the guide member (19, 23) is used in combination with the corner pin (19) and the corner guide (23), the height of the corner guide (23) is determined so that the sensor cover (5) The height of the corner pin (19) used as the positioning pin is set lower than the height of the corner pin (19) as long as it does not interfere with the counterpart when assembled to the main body (3).
On the other of the sensor cover (5) and the body body (3), the seal is provided between the inner corner wall (24) facing the corner guide (23) and the inner corner wall (24). A valve drive unit characterized in that an outer corner wall (26) forming a mounting groove (25) of the member (18) is erected toward the other side. In any one valve drive unit (1) according to claims 1-5,
The sensor cover (5) or the body body (3) on which the guide members (19, 23) are erected have a seal surface (Sb) on the body body (3) side or the sensor cover (5) side. A taper surface (27) for pressing the seal member (18) in a state where the sensor cover (5) is assembled to the body body (3) is formed on the seal surface (Sc). Valve drive unit. In any one valve drive unit (1) according to claims 1-6,
The body body (3) is a throttle body (3) forming a part of an intake system passage of the internal combustion engine,
The valve drive unit according to claim 1, wherein the valve (2) is a throttle valve (2) for adjusting an intake air amount taken in by the internal combustion engine.

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