JP2005337057A - Throttle control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To minimize leakage of air at the whole closed position on control of a throttle valve and to prevent bite-in of the seal material. <P>SOLUTION: The throttle control device has an elastic member clamped between an outer peripheral edge of the throttle valve and an inner wall surface of a suction passage and elastically deformed when the throttle valve is closed and capable of sealing a gap between the outer peripheral edge of the throttle valve and the inner wall surface of the suction passage; a rotation torque detection means capable of detecting rotation torque of a motor; an angle detection means capable of detecting a rotation angle of the throttle valve; and a whole closed position measuring means for determining the whole closed position θs on control of the throttle valve based on the rotation torque In of the motor and the rotation angle θn of the throttle valve. Thereby, the rotation angle of the throttle valve at the timing when the elastic member is started to be elastically deformed can be made to the whole closed position on the control. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a throttle control device used for adjusting an intake air amount of an engine.

A related throttle control device is described in Patent Document 1.
As shown in FIG. 7, the throttle control device has a cylindrical intake passage 92 formed in the throttle body 91, and rotates in the opening direction or the closing direction in the intake passage 92. And a disk-like throttle valve 94 for adjusting the flow rate of the flowing intake air. A seal member 96 made of a soft plastic deformation material is attached to the outer peripheral edge of the throttle valve 94. Then, when the throttle valve 94 rotates to the fully closed position for control, the seal member 96 comes into surface contact with the inner wall surface of the intake passage 92 and seals between the intake passage 92 and the throttle valve 94. That is, the action of the seal member 96 can reduce the leakage of intake air when the throttle valve 94 is fully closed.

JP-A-11-101137

In the throttle control device, the seal member 96 attached to the throttle valve 94 is formed of a plastically deformable material. For this reason, when the seal member 96 seals between the intake passage 92 and the throttle valve 94, if the seal member 96 abuts against the inner wall surface of the intake passage 92 and is deformed, the seal member 96 may move away from the inner wall surface of the intake passage 92. The deformation does not return to its original state. Therefore, for example, when the throttle body 91 is thermally expanded due to a temperature rise, a gap is formed between the seal member 96 and the inner wall surface of the intake passage 92 even when the throttle valve 94 is fully closed, and intake air leaks. May occur.
For this reason, it is conceivable that the throttle valve 94 is completely closed to the fully closed position (closed position) so that the gap is not easily generated. However, if this is done, the seal member 96 may bite between the throttle valve 94 and the inner wall surface of the intake passage 92, causing malfunction of the throttle valve 94.

  The present invention has been made to solve the above problems, and a technical problem of the present invention is that the intake passage can be closed without completely closing the throttle valve, and the state (in terms of control) In the fully closed state) is to minimize the leakage of air and prevent the sealing material from biting in.

The above-described problems are solved by the inventions of the claims.
According to the first aspect of the present invention, an intake passage formed in the throttle body and a plate-like throttle that adjusts the flow rate of the intake air flowing in the intake passage by rotating in the opening direction or the closing direction in the intake passage. A throttle control device comprising: a valve; a back spring that can hold the throttle valve at a predetermined opening position; and a motor that rotates the throttle valve in an opening direction or a closing direction against the spring force of the back spring. When the throttle valve is closed, it is elastically deformed by being sandwiched between the outer peripheral edge of the throttle valve and the inner wall surface of the intake passage, and between the outer peripheral edge of the throttle valve and the inner wall surface of the intake passage. An elastic member capable of sealing, rotational torque detecting means capable of detecting rotational torque of the motor, and rotation of the throttle valve On the basis of the angle detection means capable of detecting the degree, the rotation torque detected by the rotation torque detection means, and the rotation angle of the throttle valve detected by the angle detection means, And a fully closed position measuring means for obtaining a fully closed position.

The throttle valve receives a spring force in the direction of a predetermined opening position (opener opening position θ0 (θ0 = 6 ° to 7 °)) by a back spring. Therefore, when the throttle valve is rotated in the closing direction from the opener opening position θ0, the rotational torque of the motor increases in proportion to the rotational angle of the throttle valve due to the spring force of the back spring. When the outer peripheral edge of the throttle valve comes into contact with the inner wall surface of the intake passage through the elastic member, the elastic member is sandwiched between the outer peripheral edge of the throttle valve and the inner wall surface of the intake passage and elastically deforms. As a result, the outer peripheral edge of the throttle valve receives the elastic force of the elastic member, and the rotational torque further increases.
According to the present invention, the elastic member starts to be elastically deformed by the rotational torque detected by the rotational torque detecting means, and the timing when the outer peripheral edge of the throttle valve and the inner wall surface of the intake passage are sealed is accurately grasped. become able to. Further, the full-closed position measuring means obtains the full-closed position on the control of the throttle valve based on the rotational torque of the motor and the rotational angle of the throttle valve, so that the throttle valve at the timing when the elastic member starts elastic deformation. The rotation angle can be a fully closed position for control. For this reason, the air leakage at the fully closed position in the control of the throttle valve can be minimized, and the sealing material can be prevented from being bitten.

According to the invention of claim 2, when the ratio of the change in the rotational torque of the motor with respect to the change in the rotation angle of the throttle valve is greater than the set value, the fully closed position measuring means It can be stored as a closed position.
For this reason, it becomes possible to accurately grasp the timing when the elastic member is sandwiched between the outer peripheral edge of the throttle valve and the inner wall surface of the intake passage and starts elastic deformation.
According to the invention of claim 3, a groove is formed along the circumferential direction on the outer peripheral surface of the throttle valve, and an elastic member is fitted into the groove.
For this reason, the elastic member is surely sandwiched between the outer peripheral edge of the throttle valve and the inner wall surface of the intake passage in the fully closed position in the control of the throttle valve.

According to the invention of claim 4, a step surface is formed in the circumferential direction on the inner wall surface of the intake passage, and the elastic member attached to the outer peripheral surface of the throttle valve is in contact with the step surface. Features.
For this reason, the step surface of the intake passage functions as a rotation stopper of the throttle valve.

  According to the present invention, the intake passage can be reliably closed by the throttle valve, and the malfunction of the throttle valve caused by the elastic member biting between the throttle valve and the inner wall surface of the intake passage, or the elastic member is damaged. Can be prevented.

(Embodiment 1)
Hereinafter, the throttle control device according to the first embodiment of the present invention will be described with reference to FIGS. Here, FIG. 1 is a schematic plan view (A diagram) and a schematic diagram (B diagram) showing a rotation angle sensor of the throttle control device according to the present embodiment. 2 is a longitudinal sectional view showing the relationship between the intake passage and the throttle valve, and FIG. 3 is a plan view of the back spring. FIG. 4 is a graph showing the relationship between the valve opening (rotation angle) of the throttle valve and the operating torque, and FIG. 5 is a flowchart showing the procedure for setting the fully closed position for control of the throttle valve. FIG. 6 is a longitudinal sectional view showing a modified example of the throttle control device.

The throttle control device is a device that controls the amount of intake air flowing through the intake passage in the intake system of the engine, and includes a throttle body 1 made of resin, for example, as shown in FIG.
The throttle body 1 is formed with a substantially hollow cylindrical intake passage 1a penetrating in the vertical direction (vertical direction in FIG. 2A). An air cleaner (not shown) is connected to the upper portion of the bore portion 20, and an intake manifold (not shown) is connected to the lower portion of the bore portion 20. In addition, a metal throttle shaft 9 that traverses the intake passage 1a in the radial direction is disposed in the bore portion 20 (see FIG. 1A).

As shown in FIGS. 1 (A) and 2 (A), the throttle shaft 9 has a disk-like throttle valve 2 which can open and close the intake passage 1a by rotating with the throttle shaft 9 by screws 3. It is fixed.
In the intake passage 1 a of the throttle body 1, as shown in FIG. 2A, a stepped tapered surface 1 k that receives the outer periphery of the throttle valve 2 faces upward on the left side of the throttle shaft 9 and on the right side of the throttle shaft 9. It is formed downward. Thus, by providing the stepped tapered surface 1k in the intake passage 1a, it is not necessary to provide a rotation stopper or the like on the throttle shaft 9.

As shown in FIG. 2 (A), the throttle valve 2 is formed with a substantially equal thickness dimension from the center portion to the peripheral edge portion, and the outer peripheral edge is formed so as to be substantially opposite to the tapered surface 1k of the intake passage 1a. Has been.
That is, on the left side of the throttle shaft 9, as shown in FIG. 2 (B), the outer peripheral edge of the throttle valve 2 protrudes by a certain dimension radially outward and is continuous with the upper surface 2u of the throttle valve 2. In the state, the upper flange portion 2t is formed. On the other hand, on the right side of the throttle shaft 9, the outer peripheral edge of the throttle valve 2 has a lower portion protruding radially outward by a certain dimension, and a lower flange portion 2p is formed in a state of being continuous with the lower surface 2d of the throttle valve 2. (See FIG. 2A).

  Further, as shown in FIG. 2 (B), a semicircular groove 2e is continuously formed in the center of the thickness direction on the outer peripheral edge of the throttle valve 2 in the circumferential direction, and a cross section is formed in the semicircular groove 2e. A circular rubber sealing material 2s is fixed in a fitted state. Therefore, on the left side of the throttle shaft 9, the sealing material 2s is covered with the upper flange portion 2t from above, and on the right side of the throttle shaft 9, the sealing material 2s is supported by the lower flange portion 2p from below. Here, the outer diameter dimension of the sealing material 2s and the outer diameter dimensions of the upper flange portion 2t and the lower flange portion 2p are set to substantially equal values.

Further, as shown in FIG. 2 (B), a lower support portion 2f that supports the lower side of the sealing material 2s is formed on the outer peripheral edge of the throttle valve 2 positioned on the left side of the throttle shaft 9, and below that A tapered surface 2k is formed on the lower side of the tip of the side support portion 2f. The inclination angle of the tapered surface 2k is set to a value substantially equal to the inclination angle of the tapered surface 1k of the intake passage 1a. An upper presser portion 2z that presses the upper side of the sealing material 2s is formed on the outer peripheral edge of the throttle valve 2 positioned on the right side of the throttle shaft 9, and a tapered surface (symbol) (Not shown) is formed (see FIG. 2A). The inclination angle of the tapered surface is set to a value substantially equal to the inclination angle of the tapered surface 1k of the intake passage 1a.
With the above configuration, when the throttle valve 2 rotates to the vicinity of the closing position, the outer peripheral surface of the sealing material 2s comes into contact with the tapered surface 1k of the intake passage 1a and elastically deforms. As a result, the space between the outer peripheral edge of the throttle valve 2 and the tapered surface 1k of the intake passage 1a is sealed, and the intake passage 1a is fully closed.
That is, the sealing material 2s corresponds to the elastic member of the present invention.

As shown in FIG. 1, a throttle gear 35 s, which is a constituent member of the reduction gear mechanism 35, is fixed to the base end portion 9 b of the throttle shaft 9 while being prevented from rotating.
The reduction gear mechanism 35 receives the rotational force in the forward or reverse direction of the motor 4 and rotates the throttle shaft 9 and the throttle valve 2 in the opening direction (right direction in FIG. 2A) or in the closing direction (left direction). It is configured to let you. For this reason, when the rotation control of the motor 4 is performed by the electronic control unit (ECU), the throttle valve 2 rotates in the intake passage 1a and the flow rate of the intake air flowing through the intake passage 1a is adjusted.
Further, the rotational torque value when rotating the throttle valve 2 is detected by an electronic control unit (ECU) based on the current value of the motor 4. For this reason, an electronic control unit (ECU) corresponds to the torque detection means of the present invention.

A rotation angle sensor 40 for detecting the rotation angle of the throttle valve 2 is mounted on the output rotation shaft 4 a of the motor 4. The rotation angle sensor 40 is a sensor for obtaining the rotation angle of the throttle valve 2 based on the rotation angle of the motor 4 and the reduction gear ratio of the reduction gear mechanism 35. As shown in FIG. 54.
The movable portion 41 of the rotation angle sensor 40 is a portion that rotates together with the output rotation shaft 4a of the motor 4, and has a substantially cylindrical bottomed housing 41h, a cylindrical yoke (not shown), and a pair of magnets (not shown). ). Between the pair of magnets of the movable portion 41, the sensor main body 54 of the rotation angle sensor 40 is positioned at a specified position in a non-contact state.

The sensor body 54 detects a change in the direction of the magnetic field caused by the rotation of the movable portion 41 together with the output rotation shaft 4a of the motor 4, and based on the change in the direction of the magnetic field, the rotation angle of the motor 4 is further calculated. 2 is a device for obtaining a rotation angle of 2. That is, the sensor main body 54 detects the direction of the magnetic field and generates a signal corresponding to the direction of the magnetic field, and the rotation angle (0 ° to 360) of the motor 4 based on the signal of the magnetic detection unit 55. °), and a second calculation for calculating the rotation angle of the throttle valve 2 based on a signal from the first calculation unit 56 (rotation angle of the motor 4) and a reduction ratio of the reduction gear mechanism 35, etc. Part 57. A linear voltage signal (sensor output signal V) corresponding to the opening degree of the throttle valve 2 is output from the output terminal of the second calculation unit 57 to the electronic control unit (ECU). Note that the rotation angle of the throttle shaft 9 and the throttle valve 2 can be directly detected by the rotation angle sensor 40.
That is, the rotation angle sensor 40 corresponds to the angle detection means of the present invention.

A back spring 60 is mounted around the throttle gear 35 s constituting the reduction gear mechanism 35 described above. For example, when the power supply to the motor 4 is cut off due to a failure or the like, the back spring 60 moves the throttle valve 2 to a predetermined opening position (opener opening position θ0 (θ0 = 6 ° to 7 °)) by the spring force. Work to return to.
As shown in the plan view of FIG. 3A, the back spring 60 includes a right-handed first coil spring 62 and a left-handed second coil spring 64 connected to the first coil spring 62. The first coil spring 62 is configured to apply a closing force to the throttle valve 2 when the throttle valve 2 is positioned on the open side with respect to the opener opening position θ0. The second coil spring 64 is configured to apply an opening force to the throttle valve 2 when the throttle valve 2 is positioned closer to the opener opening position θ0.

Next, after explaining the operation of the throttle control device according to the present embodiment based on FIG. 4, a method for detecting the fully closed position in the control of the throttle valve will be explained based on FIG. 5.
When the driver steps on the accelerator pedal while the engine is started, the electronic control unit (ECU) rotates the motor 4 in the forward rotation direction, and the rotation of the motor 4 is applied to the throttle shaft 9 via the reduction gear mechanism 35. Communicated. As a result, the throttle valve 2 rotates in the opening direction against the spring force of the back spring 60 (first coil spring 62), and the intake passage 1a is opened. At this time, the relationship between the rotation angle θ of the throttle valve 2 (the output value V of the rotation angle sensor 40) and the rotation torque (current value I) of the motor 4 is represented by the characteristic 1 in FIG.

  When the driver loosens the accelerator pedal, the motor 4 is rotated in the reverse direction by the electronic control unit (ECU), the throttle valve 2 is rotated in the closing direction, and the opening degree of the intake passage 1a is decreased. At this time, since the throttle valve 2 receives a force in a direction to return to the opener opening position θ0 by the spring force of the back spring 60, the rotational torque of the motor 4 acts in a direction to suppress the spring force of the back spring 60. Therefore, the relationship between the rotational angle θ of the throttle valve 2 and the rotational torque of the motor 4 is represented by the characteristic 2 in FIG.

When the throttle valve 2 resists the spring force of the back spring 60 (second coil spring 64) and rotates in the closing direction beyond the opener opening position θ0, the opening degree of the intake passage 1a is further reduced and finally fully closed. It becomes a state. The relationship between the rotational angle θ of the throttle valve 2 and the rotational torque of the motor 4 at this time is represented by the characteristic 3 in FIG.
When the driver steps on the accelerator pedal from this state, the electronic control unit (ECU) rotates the motor 4 in the forward rotation direction, the throttle valve 2 rotates in the opening direction, and the intake passage 1a is opened. When the throttle valve 2 is on the closing side with respect to the opener opening position θ0, the throttle valve 2 receives a force in the opening direction by the back spring 60 (second coil spring 64). For this reason, the rotational torque of the motor 4 acts in a direction to suppress the spring force of the back spring 60. Therefore, the relationship between the rotational angle θ of the throttle valve 2 and the rotational torque of the motor 4 is represented by the characteristic 4 in FIG.

Next, a method for detecting the fully closed position in the throttle valve control will be described with reference to FIG. Here, the process shown in the flowchart shown in FIG. 5 is repeatedly executed at predetermined intervals in the electronic control unit (ECU).
First, when the throttle valve 2 rotates in the closing direction against the spring force of the back spring 60 (second coil spring 64) from the opener opening position θ0 (YES in step S101, YES in step S102), the constant n is 1 (initial value). ) Is set (step S103). Then, the ratio R1 between the change in the rotation angle of the throttle valve 2 (Δθ1) and the change in the rotation torque of the motor 4 (ΔI1) at the timing of n = 1 is calculated (step 104). Since n = 1 (NO in step S105), the process proceeds to step S107, and 1 is added to the constant n, so that n = 2.

  Next, at step 104, the ratio R2 between the change in the rotation angle of the throttle valve 2 (Δθ2) and the change in the rotation torque of the motor 4 (ΔI2) at the timing of n = 2 is calculated. Since n = 2 (step S105 YES), the process proceeds to step S106, and it is determined whether or not the ratio R2 is larger than the ratio R1 + α. As shown in FIG. 4B, when the sealing material 2s of the throttle valve 2 is not in contact with the inner wall surface (tapered surface 1k) of the intake passage 1a, the rotational angle change (Δθn) of the throttle valve 2 and the motor 4 Since the ratio Rn to the rotational torque change (ΔIn) is substantially constant (R1 = R2), the determination in step S106 is NO. For this reason, the process proceeds to step S107, and 1 is added to the constant n, so that n = 3.

In this way, when the processing from step S104 to step 107 is repeatedly executed and the sealing material 2s of the throttle valve 2 comes into contact with the inner wall surface (tapered surface 1k) of the intake passage 1a, the sealing material 2s is elastically deformed. Thus, the outer peripheral edge of the throttle valve 2 receives the elastic reaction force. This increases the rotational torque change (ΔIn) of the motor 4. The timing at which the sealing material 2s is elastically deformed is a changing point T in FIG.
That is, in step S106, the ratio Rn between the rotational angle change (Δθn) of the throttle valve 2 at the current timing and the rotational torque change (ΔIn) of the motor 4 is the rotational angle change (Δθn−1) of the throttle valve 2 at the previous timing. And a value (set value) obtained by adding a constant α to the ratio Rn−1 of the rotational torque change (ΔIn−1) of the motor 4 (YES in step S106). Accordingly, the rotation angle θs of the throttle valve 2 at this time is stored as a fully closed position in the control of the throttle valve 2 (step S108). Thereafter, the electronic control unit (ECU) controls the flow rate of the intake air with the rotation angle θs of the throttle valve 2 as the fully closed position for control.

Thus, since the timing at which the sealing material 2s starts elastic deformation can be stored as a fully closed position in the control of the throttle valve 2, air leakage at the fully closed position of the throttle valve 2 can be minimized, The sealing material 2s can be prevented from biting in. In addition, the life of the sealing material 2s becomes longer.
That is, the electronic control unit (ECU) corresponds to the fully closed position measuring means of the present invention.
Further, a semicircular groove 2e is formed on the outer peripheral surface of the throttle valve 2 along the circumferential direction, and a linear sealing material 2s is fitted into the semicircular groove 2e. In the fully closed position, the sealing material 2s is reliably sandwiched between the outer peripheral edge of the throttle valve 2 and the inner wall surface of the intake passage 1a.
Further, a taper surface 1k is formed in the circumferential direction on the inner wall surface of the intake passage 1a, and the sealing material 2s of the throttle valve 2 is in contact with the taper surface 1k. To function as a rotation stopper.

In the throttle control device according to the present embodiment, the configuration in which the sealing material 2s is attached to the outer peripheral edge of the throttle valve 2 is illustrated. However, as shown in FIG. 6, the shelf-shaped protrusion 1z is formed on the inner wall surface of the intake passage 1a. It is also possible to attach the sealing material 2s to the protrusion 1z.
Further, in the throttle control device according to the present embodiment, the fully closed position in control is obtained by comparing the ratio Rn of the rotational angle change (Δθn) of the throttle valve 2 and the rotational torque change (ΔIn) of the motor 4 at each timing. However, the rotational angle of the throttle valve 2 at the timing when the measured value of the rotational torque of the motor 4 exceeds the set value can be set to the fully closed position.

It is the model top view (A figure) of the throttle control apparatus which concerns on this Embodiment 1 of this invention, and the schematic diagram (B figure) showing a rotation angle sensor. FIG. 2 is a longitudinal sectional view (A diagram) showing a relationship between an intake passage and a throttle valve, and an enlarged view of a portion B in FIG. It is a top view of a back spring. FIG. 3 is a graph (A diagram) showing a relationship between a throttle valve opening (rotation angle) and an operating torque, and an enlarged view of a portion B in FIG. It is a flowchart showing the procedure which calculates | requires the fully closed position on control of a throttle valve. It is a longitudinal cross-sectional view showing the modification of a throttle control apparatus. It is a longitudinal cross-sectional view showing the conventional throttle control apparatus.

Explanation of symbols

1 Throttle body 1a Intake passage 1k Tapered surface (step surface)
2 Throttle valve 2e Semicircular groove (groove)
2s sealing material (elastic member)
4 Motor 40 Rotation angle sensor (Angle detection means)
60 Backspring ECU (electronic control unit) (rotating torque detecting means, fully closed position measuring means)

Claims (4)

An intake passage formed in the throttle body, a plate-like throttle valve that adjusts the flow rate of intake air flowing in the intake passage by rotating in the opening direction or the closing direction in the intake passage, and the throttle valve A throttle control device comprising a back spring that can be held at a predetermined opening position, and a motor that rotates the throttle valve in an opening direction or a closing direction against the spring force of the back spring,
When the throttle valve is closed, the throttle valve is elastically deformed by being sandwiched between the outer peripheral edge of the throttle valve and the inner wall surface of the intake passage, and seals between the outer peripheral edge of the throttle valve and the inner wall surface of the intake passage. Possible elastic members;
Rotational torque detecting means capable of detecting rotational torque of the motor;
Angle detection means capable of detecting the rotation angle of the throttle valve;
Fully closed position measuring means for obtaining a fully closed position for control of the throttle valve based on the rotational torque detected by the rotational torque detecting means and the rotational angle of the throttle valve detected by the angle detecting means. When,
A throttle control device comprising: The throttle control device according to claim 1,
The fully closed position measuring means is capable of storing the rotational angle of the throttle valve as a fully closed position for control when the ratio of the rotational torque change of the motor to the rotational angle change of the throttle valve becomes larger than a set value. A throttle control device. A throttle control device according to claim 1 or 2, wherein
A throttle control device, wherein a groove is formed in a circumferential direction on an outer peripheral surface of the throttle valve, and an elastic member is fitted in the groove. A throttle control device according to claim 3,
A throttle control device characterized in that a step surface is formed in a circumferential direction on the inner wall surface of the intake passage, and an elastic member attached to the outer peripheral surface of the throttle valve is in contact with the step surface.

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