JP2010265923A - Valve device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize the body of a valve device on which a spring means which carries out the function of absorbing backlash or a spring means which carries out the function of a return spring is mounted. <P>SOLUTION: A torsion bar 5, which returns an EGR valve body 3 to a predetermined opening, is arranged at the center of rotation of the EGR valve body 3. Because the spring means that carries out the function of absorbing backlash and that of the return spring is the torsion bar 5 arranged at the center of rotation of the EGR valve body 3, the body of the EGR valve device 1 can be miniaturized. Furthermore, the torsion bar 5 has a very high resonance frequency and there is no defect of resonance of the torsion bar 5 even when vehicle vibration and the like is given, so that wear or breakage by resonance can be avoided and the reliability of the EGR valve device 1 can be improved. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a valve device that opens and closes a fluid passage or changes the passage area of a fluid passage by rotating a valve element disposed in the fluid passage.

2. Description of the Related Art A valve device (such as an EGR valve device) that opens and closes a fluid passage or changes the passage area of a fluid passage by rotating a valve element disposed in the fluid passage is widely used.
The valve body is rotationally driven by a driving means having a drive source such as an electric actuator, a fluid actuator, and manual. Power transmission including a gear mechanism, a link mechanism, etc. is provided between the drive source and the valve body. Means are interposed. In the present invention, the drive source and the power transmission mechanism are collectively referred to as drive means.

The valve device is equipped with a torsion coil spring for absorbing backlash in the driving means or a torsion coil spring for returning the valve body to an initial position (for example, a fully closed position, a fully opened position, an intermediate opening position, etc.). Things are known.
This torsion coil spring has a winding diameter. For this reason, there has been a problem that mounting the torsion coil spring on the valve device increases the size of the valve device.

As a specific example, the problems of the prior art will be described with reference to the EGR valve device 1 shown in FIG. In addition, the code | symbol attaches | subjects the same code | symbol to the same functional thing according to the Example etc. which are mentioned later.
In the EGR valve device 1 shown in FIG. 10, a torsion coil spring NC is disposed so as to cover the output shaft of the drive unit 4 and the outer periphery of the drive shaft 7. However, by disposing a large-diameter torsion coil spring NC on the output shaft of the drive means 4 and the outer periphery of the drive shaft 7, the physique of the EGR valve device 1 becomes large (for example, Patent Documents 1 and 2). reference).

  On the other hand, since the torsion coil spring NC has a winding diameter, the resonance frequency (natural frequency) is relatively low. For this reason, the torsion coil spring NC used in the EGR valve device 1 is likely to resonate due to vehicle vibration or the like. If resonance occurs, there is a concern that line-to-line wear in the torsion coil spring NC may occur or breakage may occur. Therefore, the conventional EGR valve device 1 has a problem that the torsion coil spring NC must be designed by repeating trial and error.

JP 2005-233063 A JP 2007-24242

  The present invention has been made in view of the above problems, and an object of the present invention is to downsize the physique of a valve device equipped with spring means for performing at least a backlash absorption function or a return spring function. It is in.

[Means of Claim 1]
The valve device of the means of claim 1 employs a configuration in which the opening degree of the valve body is returned to a predetermined opening degree by a torsion bar arranged at the rotation center (axial core) of the valve body. Thereby, the torsion bar performs at least the function of absorbing the backlash or the function of the return spring. Thus, since the spring means that performs the function of absorbing the backlash or the function of the return spring is the torsion bar arranged at the rotation center of the valve body, the physique of the valve device can be reduced in size.
In addition, the torsion bar arranged at the center of rotation of the valve body is a rod-shaped spring, and therefore has a higher resonance frequency than a conventionally used torsion coil spring. For this reason, even in an environment that resonates when using a torsion coil spring (for example, in a vehicle-mounted environment), the torsion bar does not have a problem of resonating, and wear and breakage due to resonance can be avoided. The reliability of the valve device can be increased.

[Means of claim 2]
The fluid passage in the valve device of the means of claim 2 is an EGR flow path for returning a part of the exhaust gas of the engine to the intake side, and the valve body is an EGR valve body for adjusting the EGR amount returned to the engine.

[Means of claim 3]
The fluid passage in the valve device of the means of claim 3 is an intake passage for introducing combustion air to the engine, and the valve body is a throttle valve body for adjusting the amount of intake air sucked into the engine, or a negative pressure inside the intake passage. It is an intake valve body for generating.

[Means of claim 4]
The valve device of the means of claim 4 comprises two valve bodies (for example, a low pressure EGR valve body and an intake valve body), and two valve bodies are provided by the output of one electric motor mounted on the drive means. Are respectively rotated. And the torsion bar which returns each valve body to each predetermined opening is arrange | positioned in each rotation center of each valve body.

It is a schematic sectional drawing of an EGR valve apparatus (Example 1). It is the figure which looked at the EGR valve body from the upstream of the EGR flow path, and the expanded view of the press-molded product in an EGR valve body (Example 1). It is a graph which shows the relationship between the rotation angle of an EGR valve body, and an opening degree (Q). It is sectional drawing of the type of EGR valve apparatus which cantilever-supports an EGR valve body (Example 2). (Example 3) which is sectional drawing of the type of EGR valve apparatus of the type which supports both ends of an EGR valve body. (Example 4) which is a sectional view of the valve device which drives two valve bodies (EGR valve body and intake valve body) with one electric motor mounted in the drive means. (Example 4) which is explanatory drawing of a link mechanism. 1 is a schematic view of an intake / exhaust system of an engine. (Example 4) which is a graph which shows the relationship between the opening degree (Q) of the EGR valve body according to the rotation angle of an EGR valve body, and the opening degree (Q) of an intake valve body. It is sectional drawing of an EGR valve apparatus (conventional example).

[Description of Embodiments] will be described with reference to FIG.
The EGR valve device 1 (an example of a valve device) is rotatably supported inside an EGR channel 2 (an example of a fluid passage) that returns EGR gas (an example of fluid) to an intake side, and the EGR channel is rotated by the rotation. EGR valve body 3 (an example of a valve body) that opens and closes 2 or adjusts the opening degree, and driving means 4 (for example, an electric motor + gear speed reduction mechanism) that drives the EGR valve body 3 are provided.
A torsion bar 5 for returning the EGR valve body 3 to a fully closed position (an example of a predetermined opening) is disposed at the center of rotation of the EGR valve body 3.

Next, Embodiment 1 in which the present invention is applied to an EGR valve device 1 of an EGR device mounted on a vehicle engine will be described with reference to FIGS. In the present embodiment, the same reference numerals as those in the [DETAILED DESCRIPTION OF THE INVENTION] denote the same functional objects.
[Description of EGR device]
The EGR device returns part of the exhaust gas discharged from the engine to the intake side of the engine as EGR gas, thereby mixing EGR gas, which is non-combustible gas, into part of the intake air to suppress the combustion temperature of the engine combustion chamber, This device effectively suppresses the generation of nitrogen oxides (NOx).
The EGR device includes at least an EGR passage 2 that returns a part of exhaust gas flowing through the exhaust passage to the intake passage, and an EGR valve device 1 that adjusts the opening degree of the EGR passage 2. The EGR valve The opening degree of the device 1 is controlled by an ECU (abbreviation of engine control unit) in accordance with the traveling state of the vehicle.

  The EGR valve device 1 shown in the first embodiment is mounted on a high-pressure EGR device (see symbol H in FIG. 8) that returns EGR gas to a high negative pressure generation range in the intake passage (intake downstream of the throttle valve body). It may be a high pressure EGR valve device, or a low negative pressure EGR device that returns EGR gas to a low negative pressure generation range in the intake passage (intake upstream of the throttle valve body: for example, upstream of compressor intake in the case of a turbocharged vehicle) It may be a low-pressure EGR valve device mounted on (see symbol L in FIG. 8).

Next, the EGR valve device 1 will be described with reference to FIG. In the following, the side on which the driving means 4 is arranged (upper side in FIG. 1) is taken with reference to the EGR flow path 2 in FIG. 1, and the side different from the side on which the driving means 4 is arranged (lower side in FIG. 1). ) Is referred to as “below”, but the upper and lower directions are directions for explaining the embodiments and are not limited.
The EGR valve device 1 includes an EGR valve body 3 disposed inside the EGR flow path 2, a drive means 4 that drives the EGR valve body 3, a housing 6 that forms the EGR flow path 2, and an EGR valve body 3. A drive shaft 7 and a driven shaft 8 are provided.

The EGR valve body 3 is a butterfly valve, can open and close the EGR flow path 2 according to the rotation position, can change the opening area of the EGR flow path 2, and can change the opening area of the EGR flow path 2 Thus, the EGR amount returned to the intake passage is adjusted.
The drive means 4 is fixed to the upper part of the housing 6 and rotationally drives the drive shaft 7. The drive means 4 is a known electric motor 21 (reference numeral, see FIG. 4) that generates rotational power when energized, and this electric motor. A gear reduction mechanism 22 (reference numeral, see FIG. 4) that increases the output torque by decelerating the rotation of 21 is combined.

The main part of the housing 6 is made of an aluminum alloy die-cast, and the inner wall of the EGR channel 2 through which high-temperature EGR gas flows is provided by a member (for example, stainless steel) having excellent heat resistance and corrosion resistance. .
Here, in the EGR valve device 1 according to the first embodiment, as shown in FIG. 1, the center line of the EGR flow path 2 and the center line of the drive shaft 7 that drives the EGR valve body 3 are inclined. It is.

In the conventional EGR valve device 1, for the purpose of making the characteristics of the opening change accompanying the rotation of the EGR valve body 3 closer to the linear characteristic than the sine curve (see the broken line A in FIG. 3), the purpose is to increase the valve accuracy. As shown in FIG. 10, the EGR valve body 3 is made by a production technique close to total cutting (cutting), the EGR valve body 3 is provided with a thick plate, and the drive shaft 7 is located at the center of the EGR flow path 2. Until deeply inserted.
For this reason, in the conventional EGR valve device 1 shown in FIG. 10, when fully opened, the thick EGR valve body 3 and the drive shaft 7 inserted and arranged deeply increase the area that blocks the EGR flow path 2, The increase in ventilation resistance (high pressure loss) reduces the amount of EGR when fully opened.

In order to solve the above problems, the first embodiment employs the following technique.
The lower end of the drive shaft 7 is connected to the upper end of the EGR valve body 3 so that the insertion amount of the drive shaft 7 inserted into the EGR flow path 2 is minimized.
Similarly, the upper end of the driven shaft 8 is connected to the lower end of the EGR valve body 3 so that the insertion amount of the driven shaft 8 inserted into the EGR flow path 2 is minimized.
That is, as shown in FIG. 1, the drive shaft 7 and the driven shaft 8 are disposed in a state of being separated inside the EGR flow path 2.

  The EGR valve body 3 is supported between the drive shaft 7 and the driven shaft 8. The EGR valve body 3 is configured to open and close the EGR flow path 2. It consists of the 1st valve support part 11 connected with a lower end, and the 2nd valve support part 12 connected with the upper end of the driven shaft 8 in the lower part of the disc valve 10, from the direction along the plate surface of the disc valve 10. As shown (see FIG. 1), the disk valve 10 and the first and second valve support portions 11 and 12 form a substantially Z shape.

The three members, the disc valve 10 and the first and second valve support portions 11 and 12, are formed by pressing from a single metal plate. Thus, by providing with a press-molded product, the accuracy of the EGR valve body 3 is reduced as compared with a conventional product close to total cutting. Therefore, a seal ring 13 is provided around the press-molded disc valve 10 so as to eliminate a decrease in accuracy of the EGR valve body 3.
Specifically, in this embodiment, the seal ring 13 insert-molds the outer peripheral edge of the disc valve 10, thereby eliminating a decrease in accuracy of the EGR valve body 3 made of a press-formed product. That is, the seal ring 13 is formed so as to eliminate the accuracy error generated in the press-molded product, so that the outer peripheral edge of the seal ring 13 coincides with the inner peripheral wall of the EGR flow path 2 when the valve is closed.

The seal ring 13 of this embodiment is formed of a heat resistant resin, and as shown in FIG. 2A, the outer peripheral edge of the disc valve 10 is inserted into the resin over the entire circumference. It is.
As shown in FIG. 2 (b), the disc valve 10 has a large number of resin fixing holes 14, which provide a bonding force between the disc valve 10 made of a press-molded product and the resin seal ring 13. By raising, the seal ring 13 is provided so as not to separate from the disc valve 10 over a long period of time.

  The drive shaft 7 has a cylindrical bar shape made of a member (for example, stainless steel) having excellent heat resistance and corrosion resistance, and is arranged to extend in the vertical direction on the upper side of the housing 6, and is attached to the housing 6. The bearing 15 is rotatably supported. The bearing 15 is a rolling bearing such as a ball bearing or a roller bearing, or a sliding bearing such as a metal bearing. The bearing 15 is fixed to the inside of a bearing housing cylinder formed in the housing 6 by a coupling means such as press fitting, and has an inner circumference. The shaft member inserted through the shaft is rotatably supported.

  The lower end of the drive shaft 7 is coupled to rotate integrally with the upper portion of the EGR valve body 3 (specifically, the first valve support portion 11). As specific connecting means, in this embodiment, a detent fitting (for example, a two-side width fitting or a keyway fitting) and a welding technique (or other fixing means such as a circlip) may be used. The lower end of the drive shaft 7 and the EGR valve body 3 are connected so as to rotate integrally.

The driven shaft 8 has a cylindrical rod shape made of a member having excellent heat resistance and corrosion resistance (for example, stainless steel), and is arranged extending in the vertical direction on the lower side of the housing 6. The lower part (specifically, the second valve support part 12) is rotatably supported.
The driven shaft 8 in this embodiment is fixed to the housing 6 by press-fitting, and a bearing structure is provided at a connection portion between the driven shaft 8 and the second valve support portion 12. In this embodiment, a sliding cylinder 16 is formed by burring on the second valve support 12 to increase the contact area between the driven shaft 8 and the second valve support 12 and to suppress wear of the bearing portion. .

In the first embodiment, as described above, the technology for suppressing the amount of shaft insertion into the EGR flow path 2 by the drive shaft 7 and the driven shaft 8 and the EGR valve body 3 having a substantially Z shape made of a press-molded product are provided. Depending on the technique used, the ratio of the EGR valve element 3 closing the opening area of the EGR flow path 2 when fully opened can be suppressed to be extremely small, and the flow resistance when fully opened can be extremely small. That is, the pressure loss of the EGR valve device 1 when fully opened can be made extremely small.
Specifically, the opening area of the EGR flow path 2 changes as shown by a solid line B in FIG.
As a result, a large amount of EGR gas can be flown on the fully open side, and the EGR valve device 1 can be subjected to ultra-low pressure loss. Or since the opening area at the time of full opening can be enlarged, the EGR valve apparatus 1 can be reduced in size.

[Characteristics of Example 1]
In the EGR valve device 1 with an ultra-low pressure loss shown in the first embodiment, as described above, the EGR valve body 3 is driven via the driving means 4, and the rotation output of the electric motor 21 is the gear reduction mechanism. A structure is adopted in which the EGR valve body 3 is transmitted to the drive shaft 7 via 22 and rotated integrally with the drive shaft 7.
The EGR valve device 1 has a backlash (gap) for moving an operable mechanical element (for example, a gear train of the gear reduction mechanism 22). However, when a rotating torque reversed due to vibration or the like is applied, an impact may occur on the machine element due to backlash.

  Therefore, an EGR valve device 1 equipped with a backlash absorbing spring means is known. The backlash absorbing spring means absorbs backlash by applying a torque in a certain direction to the EGR valve device 1 and bringing a mechanical element into contact with the urging force.

Specifically, as shown in FIG. 10, the conventional EGR valve device 1 has also been proposed in which a spring means for backlash absorption is mounted. Since the spring means of the prior art uses the torsion coil spring NC, there is a problem that the physique of the EGR valve device 1 becomes large even if the arrangement position of the torsion coil spring NC is devised.
Further, since the resonance frequency of the torsion coil spring NC is relatively low, the torsion coil spring NC is likely to resonate due to vehicle vibration or the like, and there is a concern that line wear or breakage may occur due to resonance. Therefore, in the conventional EGR valve device 1, the torsion coil spring NC has to be designed by repeating trial and error.

The first embodiment employs the following technical means in order to solve the above problems.
The backlash absorbing spring means employed by the EGR valve device 1 according to the first embodiment is a torsion bar 5 (a torsion bar spring) having a straight bar shape disposed at the center of rotation of the EGR valve body 3.
The torsion bar 5 is disposed at the center of rotation of the EGR valve body 3, and the upper end of the torsion bar 5 is fixed to the drive shaft 7 (or the output shaft of the drive means 4) by caulking or welding technology. The lower end of the bar 5 is fixed to the driven shaft 8 press-fitted and fixed to the housing 6 by caulking or welding techniques. By connecting the torsion bar 5 in this way, the opening degree of the EGR valve body 3 rotated by the restoring force of the torsion bar 5 is returned to a predetermined opening degree.

  Here, the torsion bar 5 also functions as a return spring. In the first embodiment, the torsion bar 5 causes the EGR valve body 3 to be fully closed (so that the EGR valve body 3 closes the EGR flow path 2 when energization is stopped). The lower end of the torsion bar 5 is fixed so as to return to an example of a predetermined opening degree.

The torsion bar 5 is provided so that the effective length is as long as possible.
Specifically, in this embodiment, the upper end portion of the drive shaft 7 and the upper end of the torsion bar 5 are coupled to each other, and the upper insertion hole 17 through which the torsion bar 5 is inserted inside the drive shaft 7 below the coupled portion. Is formed.
Further, the lower end portion of the driven shaft 8 and the lower end of the torsion bar 5 are coupled to each other, and a lower insertion hole 18 through which the torsion bar 5 is inserted is formed inside the driven shaft 8 above the coupling portion.

  Further, as shown in FIG. 2 (b), a punching hole 19 for inserting and arranging the torsion bar 5 is formed at the center of the disc valve 10. This punching hole 19 is closed by a closing member 20 fixed to the disc valve 10 as shown in FIG. The closing member 20 is a member that fills a gap between the torsion bar 5 and the disc valve 10 in the punching hole 19 and is formed integrally with the seal ring 13 by a resin that forms the seal ring 13. is there. An insertion hole 20 a into which the torsion bar 5 is inserted is formed at the center of the closing member 20. Only a fine sliding clearance is formed between the insertion hole 20 a and the torsion bar 5, and leakage of EGR gas from the insertion part of the torsion bar 5 is prevented.

(Effect of Example 1)
As described above, the EGR valve device 1 according to the first embodiment employs a configuration in which the opening degree of the EGR valve body 3 is returned to the fully closed position by the torsion bar 5 disposed at the rotation center of the EGR valve body 3. . Thereby, the torsion bar 5 fulfills the function of absorbing the backlash and the function of the return spring.
Thus, since the spring means that performs the backlash absorption function and the return spring function is the torsion bar 5 disposed at the center of rotation of the EGR valve body 3, the size of the EGR valve device 1 can be reduced. Can do.
Further, the torsion bar 5 has a very high resonance frequency as compared with the conventionally used torsion coil spring NC. For this reason, even if vehicle vibration or the like is applied, there is no problem that the torsion bar 5 resonates, wear and breakage due to resonance can be avoided, and the reliability of the EGR valve device 1 can be improved.

A second embodiment will be described with reference to FIG. In the following embodiments, the same reference numerals as those in the first embodiment denote the same functional objects.
In the first embodiment, the present invention is applied to the EGR valve device 1 having an ultra-low pressure loss in which the shaft insertion amount into the EGR flow path 2 is reduced as much as possible and the EGR valve body 3 is thinned by using a press-molded product. An example is shown.
On the other hand, in the second embodiment, the EGR valve body 3 is manufactured by a production technique close to total cutting as in the prior art, and the EGR valve body 3 is cantilevered only by the upper drive shaft 7. The present invention is applied to 1.

  The torsion bar 5 of this embodiment is inserted through the center of the drive shaft 7, and the upper end of the torsion bar 5 is fixed to the upper end of the drive shaft 7 (or the output shaft of the drive means 4). The lower end of the bar 5 is fixed through a press-fitting member 23 press-fitted into the housing 6. Of course, a fine sliding clearance is provided between the EGR valve body 3 and the torsion bar 5 so that the torsion bar 5 can be displaced relative to the EGR valve body 3.

A third embodiment will be described with reference to FIG.
In the second embodiment, the example in which the present invention is applied to the EGR valve device 1 that cantilever-supports the EGR valve body 3 is shown.
On the other hand, in the third embodiment, the present invention is applied to the EGR valve device 1 in which the EGR valve body 3 is supported at both ends by the drive shaft 7 extending downward. Specifically, the present invention is applied to the EGR valve device 1 having a structure in which drive shafts 7 that apply a driving force to the EGR valve body 3 are rotatably supported by bearings 15 disposed above and below the EGR valve body 3, respectively. Is.

A fourth embodiment will be described with reference to FIGS.
In the fourth embodiment, the present invention is also applied to an intake valve device 31 for generating a negative pressure in an intake passage 32 that guides combustion air to the engine.
The fourth embodiment shows a composite valve device that drives the low-pressure EGR valve device 1 ′ and the intake valve device 31 by one drive means 4. Note that the low-pressure EGR valve device 1 ′ performs the same function as the EGR valve device 1 described above.

  Specifically, the fourth embodiment is mounted on the low pressure EGR valve body 3 ′ mounted on the low pressure EGR valve device 1 ′ and the intake valve device 31 based on the output of one electric motor 21 mounted on the driving means 4. As shown in FIG. 6, the opening of the low pressure EGR valve body 3 ′ is returned to the fully closed position at the center of rotation of the low pressure EGR valve body 3 ′. A torsion bar 5 for a low pressure EGR valve that applies an urging force is disposed, and a torsion bar 5 ′ for an intake valve that applies an urging force that returns the opening of the intake valve body 33 to the fully open position at the center of rotation of the intake valve body 33. Is to arrange.

Next, an application example of the valve device of the fourth embodiment will be described with reference to FIGS.
In addition to the high-pressure EGR device H, a vehicle engine intake / exhaust system that includes a low-pressure EGR device L has been proposed.
The high pressure EGR device H is good at returning a large amount of EGR gas to the engine by connecting the exhaust upstream side of the exhaust passage 34 having a high exhaust pressure and the intake downstream side of the intake passage 32 having a high intake negative pressure. Exhaust gas recirculation device.

  The low pressure EGR device L is good at returning a small amount of EGR gas to the engine by connecting the exhaust downstream side of the exhaust passage 34 having a low exhaust pressure and the intake upstream side of the intake passage 32 having a low intake negative pressure. The exhaust gas recirculation device includes a low pressure EGR flow path 2 ′ that returns a part of the exhaust gas to the intake upstream side of the intake passage 32 as EGR gas. As a specific example of the low pressure EGR flow path 2 ′, an exhaust passage 34 on the exhaust downstream side of the DPF 34 a and an intake passage 32 on the intake upstream side of the compressor 32 a of the turbocharger are connected.

The low pressure EGR valve body 3 ′ of the fourth embodiment performs opening / closing and opening degree adjustment of the low pressure EGR flow path 2 ′.
Further, the intake valve body 33 of the fourth embodiment varies the opening degree of the intake upstream of the connection portion of the low pressure EGR flow path 2 ′ in the intake passage 32, and the connection of the low pressure EGR flow path 2 ′ in the intake passage 32. This is for generating the intake negative pressure in the part. Here, the intake valve body 33 is provided so as to open a part of the intake passage 32 even when the intake passage 32 is squeezed to the maximum (see the minimum opening of the broken line Y in FIG. 9). ). 9 indicates the opening degree of the low pressure EGR valve body 3 ′ with respect to the rotation angle of the low pressure EGR valve body 3 ′, and the broken line Y indicates the opening degree of the intake valve body 33 with respect to the rotation angle of the low pressure EGR valve body 3 ′. Is shown.

The low pressure EGR device L is good at returning a small amount of EGR gas to the engine. However, even if there is an operation region in which a large amount of EGR gas is to be returned to the engine using the low pressure EGR device L, the low pressure EGR device L having a structure for returning the EGR gas to the low intake negative pressure generation range causes the engine to generate a large amount of EGR gas. It is difficult to return.
Therefore, the low pressure EGR device L is provided with an intake valve body 33 for generating negative intake pressure at the connection portion of the low pressure EGR flow path 2 ′ in the intake passage 32, and the low pressure EGR device L is an operating region where a large EGR amount is desired. Then, the opening degree is controlled in the direction in which the intake valve body 33 is closed (the direction in which the intake negative pressure is generated), and a large amount of EGR gas is controlled in the low pressure EGR device L.

However, the intake valve body 33 needs to reduce the opening degree of the intake valve body 33 so as to generate negative pressure only in an operation region in which a large amount of EGR gas is returned to the engine using the low pressure EGR device L. In the operation region, it is necessary to maximize the opening degree of the intake valve body 33 so that the intake valve body 33 does not generate negative pressure.
The opening degrees of the low pressure EGR valve body 3 ′ and the intake valve body 33 are set based on different operating factors.
For this reason, in the existing technology, a dedicated electric actuator for driving the low pressure EGR valve body 3 ′ and a dedicated electric actuator for driving the intake valve body 33 are required, which increases the cost, the physique, and the weight. It was a factor of up.

Therefore, in the fourth embodiment, the opening required for the low pressure EGR valve body 3 ′ and the opening required for the intake valve body 33 are achieved by one driving means 4.
In order to satisfy the opening requirements of the low pressure EGR valve body 3 ′ and the intake valve body 33 with one drive means 4, the drive means 4 is equipped with a link mechanism R separately from the electric motor 21 and the gear reduction mechanism 22. ing.
The low pressure EGR valve body 3 ′ is connected to the output shaft of the gear reduction mechanism 22 driven by the electric motor 21 and is driven by the gear reduction mechanism 22.
The intake valve body 33 is driven by a link mechanism R that converts the rotational displacement of the low-pressure EGR valve body 3 ′ to an opening required for the intake valve body 33.

  The link mechanism R is shown in FIG. 7 and includes a link plate 35 that rotates integrally with the low-pressure EGR valve body 3 ′, and a link lever 36 that rotates integrally with the intake valve body 33. The link plate 35 is formed with a cam groove 37, and the link lever 36 is provided with a meshing pin 38 (for example, a roller that is rotatably supported) that fits into the cam groove 37.

The cam profile of the cam groove 37 is a combination of two groove shapes.
One groove shape of the cam groove 37 is an arc groove having the same center as the rotation center of the low-pressure EGR valve body 3 ′, and the opening degree of the low-pressure EGR valve body 3 ′ maximizes the low-pressure EGR flow path 2 ′. In the valve closing side opening range (opening range of 0 ° to opening degree Z) from the EGR side rotation angle = 0 ° to the predetermined switching opening degree Z, the opening degree of the intake valve body 33 is maximized. It is provided to keep the opening.

The other groove shape of the cam groove 37 is a groove (arc groove, linear groove, etc.) that changes at a predetermined angle with respect to the arc groove having the same center as the rotation center of the low pressure EGR valve body 3 ′. As the opening degree of 3 ′ changes from the predetermined switching opening degree Z to the maximum opening degree (EGR side rotation angle = 90 ° in FIG. 9), the link lever 36 is rotated to maximize the opening degree of the intake valve body 33. It is provided so as to rotate in the direction of closing the intake passage 32 from the opening degree.
By adopting the above configuration, both the low pressure EGR valve body 3 ′ and the intake valve body 33 can be driven by one electric motor 21, and as shown in FIG. 9, the low pressure EGR valve body 3 ′ is required. Both the characteristics and the characteristics required for the intake valve body 33 can be satisfied.

  Then, as described above, the gear reduction mechanism 22 is provided by providing the torsion bar 5 that gives the urging force for returning the opening of the low pressure EGR valve body 3 ′ to the fully closed position at the rotation center of the low pressure EGR valve body 3 ′. The torsion bar 5 ′ that can absorb the backlash of the intake valve body 33 and applies a biasing force that returns the opening degree of the intake valve body 33 to the fully open position at the rotational center of the intake valve body 33 is provided. Backlash can be absorbed.

The predetermined opening degree of the valve element returned by the torsion bar 5 may be a fully closed position, a fully open position, or an intermediate position (half opening) between the fully closed position and the fully open position. .
In the above embodiment, the present invention is applied to the EGR valve device 1 (including the low pressure EGR valve device 1 ′) or the intake valve device 31. However, the present invention is applied to a throttle valve device that adjusts the intake air amount sucked into the engine. The present invention may be applied. Furthermore, the fluid to be controlled is not limited to exhaust gas or intake air, and the present invention may be applied to other valve devices that perform opening / closing of gas fluid or liquid fluid and adjusting flow rate or pressure.

1 EGR valve device 1 'Low pressure EGR valve device 2 EGR flow path (fluid passage)
2 'Low pressure EGR flow path (fluid path)
DESCRIPTION OF SYMBOLS 3 EGR valve body 3 'Low pressure EGR valve body 4 Drive means 5 Torsion bar used for EGR valve apparatus (or low pressure EGR valve apparatus) 5' Torsion bar 21 used for intake valve apparatus Electric motor 22 Gear reduction mechanism 31 Intake valve apparatus 32 Intake passage (fluid passage)
33 Intake valve body R Link mechanism

Claims (4)

Valve body (3, 3 ', 33) which is rotatably supported inside the fluid passage (2, 2', 32) through which the fluid can pass and which opens and closes or adjusts the opening degree of the fluid passage by rotation. When,
Drive means (4) for driving the valve body;
In the valve device (1, 1 ', 31) comprising:
A valve device in which a torsion bar (5, 5 ') for returning the opening degree of the valve body to a predetermined opening degree is arranged at the center of rotation of the valve body. The valve device according to claim 1,
The fluid passage is an EGR flow path (2) that returns part of the exhaust gas of the engine to the intake side, and the valve body is an EGR valve body (3) that adjusts the amount of EGR returned to the engine. A valve device characterized by that. The valve device according to claim 1,
The fluid passage is an intake passage (32) that guides combustion air to the engine;
The valve body is a throttle valve body for adjusting an intake air amount sucked into the engine or an intake valve body (33) for generating a negative pressure in the intake passage (32). apparatus. In the valve apparatus in any one of Claims 1-3,
This valve device is a composite valve device including two valve bodies (3 ′, 33), and the two valve bodies are output by the output of one electric motor (21) mounted on the drive means (4). (3 ′, 33) are operated to rotate,
The torsion bar (5, 5 ') for returning the valve body to a predetermined opening degree is arranged at the center of rotation of each valve body (3', 33). Valve device to do.

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