JP2014066288A - Exhaust valve, and spring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce striking sound generated with chattering of a valve member.SOLUTION: A resistive element 15C that can be slidably contacted with a coil part 15A is contacted with an outer peripheral side of the coil part 15A of a spring 15 acting as a return spring for a valve body. With this action, a part of kinetic energy of the valve body generated by a displacement of the valve body is converted into heat energy without being stored as resilient energy in the spring 15 and absorbed into the surrounding atmosphere. Accordingly, since the kinetic energy of the valve body generated as the chattering of the valve body can be absorbed as heat energy, the chattering of the valve body can be attenuated. Consequently, the chattering or the like generated along with the chattering of the valve body can be reduced.

Description

  The present invention relates to an exhaust valve and a spring for the exhaust valve.

  For example, in the invention described in Patent Document 1, a wire mesh is disposed on a valve seat portion that contacts the valve body as means for reducing impact sound or hammering sound when the valve body chatters or vibrates. That is, when the valve body vibrates and the valve body collides with the wire mesh, the collision load is dispersed, so that the impact sound or the hitting sound is reduced. Hereinafter, chattering or vibration is referred to as chattering.

JP 2011-185119 A

  However, in the invention described in Patent Document 1, only the collision load is dispersed, and chattering of the valve body is not prevented in the first place, so it is difficult to reduce the hitting sound or the like caused by the chattering of the valve body. .

  An object of this invention is to reduce the hitting sound etc. which arise with chattering of a valve body in view of the said point.

  In order to achieve the above object, the present invention is an exhaust valve for controlling the flow of exhaust gas discharged from an internal combustion engine (3) according to the invention described in claim 1, and is displaceable in a flow path of exhaust gas. And a damping part that converts the kinetic energy of the valve body (11) generated by the displacement of the valve body (11) into thermal energy and absorbs it. .

  Thereby, in the invention according to the first aspect, since the kinetic energy generated along with the chattering of the valve body (11) can be absorbed as thermal energy, the chattering of the valve body (11) can be attenuated. Therefore, it is possible to reduce the hitting sound and the like generated with the chattering of the valve body (11).

  That is, the invention described in claim 1 is not an invention based on the principle of dispersing the collision load, but rather absorbs the kinetic energy generated by chattering as thermal energy, thereby reducing chattering and hitting sound. Etc. are reduced.

  According to the second aspect of the present invention, the spring (15) that causes the valve body (11) to act on the valve body (11) with an elastic force in a direction to close the flow path is provided, and the damping portion is a friction generated with the deformation of the spring (15). It is characterized by absorbing kinetic energy by heat.

Thus, in the invention according to the second aspect, like the friction damper, the kinetic energy generated with chattering can be converted into thermal energy and absorbed.
And since it is the structure which produces friction heat at the time of a deformation | transformation of a spring (15), compared with the exhaust valve etc. of patent document 1 which arrange | positioned the wire mesh in the valve seat part, chattering is attenuated with a simple structure. It is possible to reduce the hitting sound and the like.

Further, for a normal exhaust valve that does not have a measure for reducing the sound of hitting, chattering can be attenuated to reduce the sound of hitting and the like without greatly changing the configuration.
In the invention according to claim 3, the damping part is provided with a resistor (15C) that comes into slidable contact with the spring (15), and the spring (15) is resisted by the elastic deformation of the spring (15). Friction heat is generated by sliding contact with the body (15C).

  Thus, in the invention described in claim 3, by changing the contact pressure between the resistor (15C) and the spring (15), the frictional heat generated when the spring (15) is deformed can be easily adjusted. It can easily cope with exhaust valves of various specifications.

The invention according to claim 4 is characterized in that the resistor (15C) has a spring material that can be elastically deformed in accordance with the deformation of the spring (15).
Thereby, in invention of Claim 4, since it can suppress that the contact pressure of a resistor (15C) and a spring (15) changes greatly with a deformation | transformation of a spring (15), a valve body (11 ) Can be absorbed as heat energy without fail.

  In the invention according to claim 5, the spring (15) is a torsion coil spring having a coil portion (15A) in which a wire is wound in a coil shape, and the resistor (15C) is a coil portion (15A). It is characterized by being in contact with the outer peripheral side or the inner peripheral side.

  In the invention according to claim 6, the resistor (15C) is a cylindrical body disposed on the outer peripheral side of the coil portion (15A), and further, the resistor (15C) is the coil portion (15A). A slit portion (15D) is provided which extends in a direction parallel to the axial direction and makes the resistor (15C) discontinuous in the circumferential direction.

  By the way, when the deformation of the coil portion (15A) proceeds, the outer diameter of the coil portion (15A) gradually decreases. At this time, since the resistor (15C) is configured to have an elastically deformable spring material, the resistor (15C) is also reduced in diameter so as to follow the reduced diameter of the coil portion (15A).

  However, in the invention according to claim 6, since the slit (15D) is provided in the resistor (15C), when the diameter of the resistor (15C) is reduced, the slit width of the slit (15D) is gradually reduced. As a result, the slit portion (15D) is finally lost. And if a slit part (15D) lose | disappears, the diameter reduction of a resistor (15C) will stop.

  That is, in the invention described in claim 6, when the deformation amount of the coil portion (15A) is equal to or less than a predetermined amount, that is, until the slit portion (15D) disappears, the resistor (15C) and the coil portion ( 15A) is in sliding contact with it and frictional heat is generated. When the amount of deformation of the coil portion (15A) exceeds a predetermined amount, the diameter of the resistor (15C) stops, so that the resistor (15C) and the coil portion (15A) are not in contact with each other and friction is generated. Disappear.

  Further, chattering of the valve body (11) can be regarded as vibration having a specific amplitude. On the other hand, when the valve body (11) is opened and closed, the valve body (11) is displaced to a range exceeding the specific amplitude.

  Therefore, if the slit width of the slit portion (15D) is selected so that the predetermined amount of deformation becomes the specific amplitude, when the valve body (11) is chattering, the resistance body (15C) When the frictional heat is generated by sliding contact with the coil portion (15A) and the valve body (11) is opened / closed, the resistor (15C) and the coil portion (15A) are configured not to contact each other. It becomes possible.

  Therefore, if the slit width of the slit portion (15D) is selected as described above, it is possible to suppress the operation of the valve body (11) from being inhibited while effectively attenuating chattering of the valve body (11).

  According to the seventh aspect of the present invention, the valve element (11) is applied to the exhaust valve (10) for controlling the flow of the exhaust discharged from the internal combustion engine (3), and is displaceably disposed in the exhaust flow path. Of the spring body (15A) that is elastically displaced in conjunction with the displacement of the valve body (11) and the valve body (11) that is generated by the displacement of the valve body (11). And an attenuation unit that converts kinetic energy into heat energy and absorbs the energy.

Thereby, in the invention described in claim 7, as in the case described in claim 1, it is possible to reduce the hitting sound and the like caused by the chattering of the valve body (11).
The invention according to claim 8 is characterized in that the damping part absorbs kinetic energy by frictional heat generated with deformation of the spring body (15A).

Thus, in the invention according to claim 8, similarly to the invention according to claim 2, the kinetic energy generated accompanying chattering can be converted into heat energy and absorbed.
In the ninth aspect of the present invention, the damping section includes a resistor (15C) that is slidably contacted with the spring body (15A), and the spring body (15A) according to the elastic deformation of the spring body (15A). ) Is brought into sliding contact with the resistor (15C) to generate frictional heat.

  Thus, in the invention described in claim 9, similarly to the invention described in claim 3, by changing the contact pressure between the resistor (15C) and the spring (15), the spring (15) is deformed. Since the generated frictional heat can be easily adjusted, it is possible to easily cope with exhaust valves of various specifications.

The invention according to claim 10 is characterized in that the resistor (15C) has a spring material that can be elastically deformed in accordance with the deformation of the spring body (15A).
As a result, in the invention described in claim 10, as in the invention described in claim 4, the contact pressure between the resistor (15C) and the spring (15) changes greatly as the spring (15) is deformed. Therefore, the kinetic energy generated with the chattering of the valve body (11) can be reliably absorbed as thermal energy.

  In the invention according to claim 11, the spring body (15A) is configured in a coil shape in which a wire is wound in a coil shape, and the resistor (15C) is formed on the outer peripheral side of the spring body (15A) or It is in contact with the inner peripheral side.

  In the invention described in claim 12, the resistor (15C) is a cylindrical body disposed on the outer peripheral side of the spring body (15A), and further, the resistor (15C) includes a spring body (15A). A slit portion (15D) is provided which extends in a direction parallel to the axial direction of the resistor and makes the resistor (15C) discontinuous in the circumferential direction.

  Thus, in the invention of the twelfth aspect, similarly to the invention of the sixth aspect, if the slit width of the slit portion (15D) is selected, the chattering of the valve body (11) is effectively attenuated. Inhibiting the operation of the valve body (11) can be suppressed.

  Incidentally, the reference numerals in parentheses for each of the above means are examples showing the correspondence with the specific means described in the embodiments described later, and the present invention is indicated by the reference numerals in the parentheses of the above respective means. It is not limited to specific means.

1 is a schematic diagram of an exhaust system in which an exhaust valve 10 according to an embodiment of the present invention is used. It is AA sectional drawing of FIG. (A) is a front view of the spring 15 which concerns on 1st Embodiment of this invention, (b) is a top view of Fig.3 (a). It is a characteristic view of the spring 15 which shows the characteristic of this invention. (A) is a front view of the spring 15 which concerns on 2nd Embodiment of this invention, (b) is a top view of Fig.5 (a). (A) is a front view of the spring 15 which concerns on 3rd Embodiment of this invention, (b) is a top view of Fig.6 (a). It is a figure which shows the characteristic of the spring 15 which concerns on 4th Embodiment of this invention. (A) is a front view of the spring 15 which concerns on 5th Embodiment of this invention, (b) is the A section enlarged view of Fig.8 (a). It is the graph which measured the acceleration which arises in the valve body 11 in the exhaust valve 10 using three types of springs from which the initial tension at the time of coiling differs. It is a figure which shows the structure of the exhaust valve 10 which concerns on 6th Embodiment of this invention.

  The “embodiment of the invention” described below shows an example of the embodiment. In other words, the invention specific items described in the claims are not limited to the specific means and structures shown in the following embodiments.

In this embodiment, the exhaust valve and the exhaust valve spring according to the present invention are applied to an exhaust heat recovery device for a vehicle. Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
1. Outline of Exhaust Heat Recovery Device As shown in FIG. 1, the exhaust heat recovery device 1 is a device that recovers heat from exhaust gas discharged from an internal combustion engine 3 such as a gasoline engine or a diesel engine.

  The exhaust heat recovery device 1 according to the present embodiment recovers heat from the exhaust by exchanging heat between the cooling water of the internal combustion engine 3 and the exhaust. Incidentally, the heat recovered in the cooling water is used for warming up the internal combustion engine 3 or heating the passenger compartment.

The heat exchanger 1A of the exhaust heat recovery device 1 is provided in the exhaust pipe 5 through which the exhaust flows. In this heat exchanger 1A, exhaust paths 1B and 1C through which exhaust flows are provided.
The exhaust valve 10 controls the flow state of the exhaust gas flowing through the exhaust path 1B. The exhaust valve 10 performs switching control between when exhaust flows into the silencer 7 via the exhaust path 1B and when exhaust flows around the exhaust path 1B and flows into the silencer 7.

That is, when the exhaust path 1C is closed by the exhaust valve 10, the exhaust gas that has lost its place of flow flows into the exhaust path 1B communicating with the exhaust path 1C, so that heat is recovered by the heat exchanger 1A.
On the other hand, when the exhaust passage 1C is opened by the exhaust valve 10, the exhaust gas flowing directly from the exhaust passage 1C to the silencer 7 without flowing through the exhaust passage 1B increases as the opening increases. The heat recovered in the vessel 1A is reduced.

2. Structure of Exhaust Valve and Exhaust Valve Spring As shown in FIG. 2, the exhaust valve 10 includes a valve body 11, a drive shaft 13, a spring 15, an actuator 17, and the like. As shown in FIG. 1, the valve body 11 is a movable body that is displaceably disposed in the exhaust flow path, and is located between a position at which the exhaust flow downstream of the exhaust path 1 </ b> C is closed and a position at which it is opened. Oscillating displacement.

  The drive shaft 13 is a swing shaft that holds the valve body 11 and displaces the valve body 11. As shown in FIG. 2, the drive shaft 13 is rotatably held by the shaft casing 13A via the bearing portion 13B at both axial ends while being housed in a cylindrical shaft casing 13A.

  Since the valve body 11 is located in the exhaust passage, the shaft casing 13A and the drive shaft 13 are disposed so as to penetrate the inside and outside of the housing 1D that houses the heat exchanger 1A.

  The spring 15 is a spring that applies an elastic force to the valve body 11 in a direction to close the exhaust passage 1 </ b> C. The spring 15 according to the present embodiment is disposed on one end side in the axial direction of the drive shaft 13 and indirectly applies the elastic force to the valve body 11 via the drive shaft 13.

  Further, as shown in FIG. 3, the spring 15 is a torsion coil spring having a coil portion 15A, a pair of hook portions 15B, and the like. The coil portion 15A is a spring body in which a wire is wound in a coil shape.

  And the drive shaft 13 has penetrated the inside of the coil part 15A, as shown in FIG. One hook portion 15B of the pair of hook portions 15B is locked to the drive shaft 13, and the other hook portion 15B is locked to the shaft casing 13A or a fixing member around the shaft casing 13A.

  For this reason, when the valve body 11 is displaced to a position where the exhaust passage 1C is opened, the coil portion 15A is twisted. Therefore, the inner diameter of the coil portion 15A is reduced while increasing the contact surface pressure with the adjacent wire. (Hereinafter referred to as “reducing diameter”).

  Further, as shown in FIG. 3, a resistor 15 </ b> C that is slidably contacted with the outer periphery of the coil portion 15 </ b> A is provided on the outer periphery side of the coil portion 15 </ b> A. The resistor 15C constitutes an attenuating portion that generates frictional heat by slidingly contacting the outer periphery of the coil portion 15A with the elastic deformation of the coil portion 15A.

  That is, the resistor 15C is configured to include an elastically deformable spring material 15E such as a spring steel plate and a friction material 15F that is in sliding contact with the coil portion 15A. As shown in FIG. 3B, the spring material 15E is formed in a substantially C shape so as to wind the outer periphery of the coil portion 15A. The friction material 15F is disposed on the inner peripheral side of the spring material 15E and is pressed against the outer periphery of the coil portion 15A by the spring material 15E.

  As shown in FIG. 3A, the resistor 15C is a cylindrical body disposed on the outer peripheral side of the coil portion 15A, and a part thereof is parallel to the axial direction of the coil portion 15A. A slit portion 15D that extends in the direction and makes the resistor 15C discontinuous in the circumferential direction is provided.

  Further, the resistor 15C is in close contact with the outer periphery of the coil portion 15A in a state of being elastically deformed so that the inner diameter thereof is enlarged as compared with that before being attached to the spring 15. For this reason, when the spring 15 is elastically deformed and the coil portion 15A is reduced in diameter, the resistor 15C is also reduced in diameter so as to follow this.

  Incidentally, the friction material 15F according to the present embodiment is a metal mesh, and by adjusting the material and bulk density of the friction material 15F and the spring characteristics of the spring material 15E, the resistor 15C and the coil portion when the spring 15 is elastically deformed. The frictional force and the frictional heat generated with 15A can be adjusted.

  As shown in FIG. 2, the actuator 17 acts on the drive shaft 13 to displace the valve body 11 to a position where the exhaust path 1 </ b> C is opened against the elastic force of the spring 15. The actuator 17 according to the present embodiment is an electromagnetic actuator such as a solenoid.

3. Characteristics of Spring According to this Embodiment The graph shown in FIG. 4 shows the drive shaft when the valve body 11 is displaced from the closed state to the open state, and when the valve body 11 is displaced from the open state to the closed state. 13 shows the relationship between the torque (moment) acting on 13 and the operating angle (relative angle of the hook portion 15B).

  In FIG. 4, the solid line is a graph showing the characteristics of the spring 15 according to the present embodiment, and the alternate long and short dash line is a graph showing the characteristics of the spring 15 according to the second to fourth embodiments, which will be described later. These are the graphs which show the characteristic of the spring 15 which concerns on 5th Embodiment mentioned later.

  And since friction arises because the outer periphery of the coil part 15A and the resistor 15C come into sliding contact with the elastic deformation of the coil part 15A, as shown in FIG. 4, the valve element 11 is changed from the closed state to the opened state. The torque with respect to the operating angle differs between when the valve body 11 is displaced and when the valve body 11 is displaced from the open state to the closed state.

  That is, in the initial stage when the valve body 11 starts to open from the state where the valve body 11 is closed and stationary (hereinafter referred to as the forward path initial stage), the static frictional force mainly acts on the spring 15. The increase in the operating angle is small with respect to the increase in torque. When the torque further increases, the dynamic friction force mainly acts on the spring 15, so that the amount of increase in the operating angle with respect to the amount of increase in torque is greater than in the initial stage of the forward path.

  In the initial stage when the valve body 11 starts to close from the state where the valve body 11 is open and stationary (hereinafter referred to as the initial stage of the return path), the static frictional force is mainly generated by the spring as in the initial stage of the forward path. 15, the amount of decrease in the operating angle is smaller than the amount of torque decrease. When the torque is further reduced, the dynamic frictional force mainly acts on the spring 15, so that the amount of decrease in the operating angle with respect to the amount of decrease in the torque is greater than in the initial stage of the return path.

  Note that the main reason why the rate of change in the initial stage of the outward path and the rate of change in the initial stage of the return path are different is the inherent characteristics of the spring 15 itself, and the resistor 15C and the coil portion 15A that change with the deformation of the spring 15. This is a change in contact surface pressure.

  And the energy equivalent to the area enclosed by the graph shown in FIG. 4 is discharge | released in the atmosphere as frictional heat, without being stored in the spring 15 as elastic energy. In other words, a part of the kinetic energy of the valve body 11 generated by the displacement of the valve body 11 is converted into heat energy and absorbed in the atmosphere without being stored as elastic energy in the spring 15. .

  Therefore, in this embodiment, since the kinetic energy of the valve body 11 generated along with the chattering of the valve body 11 can be absorbed as thermal energy, the chattering of the valve body 11 can be attenuated. As a result, it is possible to reduce the hitting sound and the like that accompanies chattering of the valve body 11.

  Further, in this embodiment, kinetic energy is absorbed by frictional heat generated as the spring 15 is deformed. Therefore, compared to the exhaust valve 10 described in Patent Document 1, the chattering is damped with a simple configuration. Sound and the like can be reduced.

Further, for a normal exhaust valve 10 that has not been subjected to a sound reduction measure, chattering can be attenuated to reduce sound and the like without greatly changing the configuration.
Further, in the present embodiment, the frictional heat generated when the spring 15 is deformed can be easily adjusted by changing the contact pressure between the resistor 15C and the spring 15, and thus the exhaust valve 10 having various specifications. Can be easily dealt with.

  Further, in the present embodiment, the resistor 15C is configured to have a spring material that can be elastically deformed with the deformation of the spring 15, so that the contact pressure between the resistor 15C and the spring 15 is It is possible to suppress a large change accompanying the deformation of the spring 15. Therefore, the kinetic energy generated as a result of chattering of the valve body 11 can be reliably absorbed as thermal energy.

  By the way, as the deformation of the coil portion 15A proceeds, the outer diameter of the coil portion 15A gradually decreases. At this time, since the resistor 15C has a spring material that can be elastically deformed, the resistor 15C is also reduced in diameter so as to follow the reduced diameter of the coil portion 15A.

  However, since the resistor 15C is provided with the slit portion 15D, when the diameter of the resistor 15C is reduced, the slit width of the slit portion 15D gradually decreases, and finally, the state where the slit portion 15D disappears. Become. When the slit portion 15D disappears, the diameter of the resistor 15C stops.

  That is, in the present embodiment, when the amount of deformation of the coil portion 15A is equal to or less than a predetermined amount, that is, until the slit portion 15D is lost, the resistor 15C and the coil portion 15A are in sliding contact to generate frictional heat. . When the amount of deformation of the coil portion 15A exceeds a predetermined amount, the diameter of the resistor 15C stops, so that the resistor 15C and the coil portion 15A are not in contact with each other and friction is lost.

  Further, the chattering of the valve body 11 can be regarded as vibration having a specific amplitude. On the other hand, when the valve body 11 is opened and closed, the valve body 11 is displaced to a range exceeding the specific amplitude.

  Therefore, in the present embodiment, the slit width of the slit portion 15D is selected so that the predetermined amount of deformation has the specific amplitude. Thus, (1) when the valve body 11 is chattering, the resistor 15C and the coil portion 15A are in sliding contact to generate frictional heat. (2) When the valve body 11 is opened and closed, the resistor 15C The coil part 15A is not in contact.

  Therefore, in this embodiment, chattering of the valve body 11 can be effectively attenuated, and when the valve body 11 is opened and closed, the resistor 15C and the coil portion 15A do not slide, so the valve body It can suppress that the operation | movement of 11 will be inhibited.

(Second Embodiment)
In the first embodiment, the resistor 15C is disposed on the outer peripheral side of the coil portion 15A. However, in the present embodiment, as shown in FIG. 5, the resistor 15C is disposed on the inner peripheral side of the coil portion 15A. It is.

  In the first embodiment, since the resistor 15C is disposed on the outer peripheral side of the coil portion 15A, when the operating angle increases and the diameter of the coil portion 15A progresses, the resistor 15C is generated accordingly. The frictional force is reduced.

  On the other hand, in this embodiment, since the resistor 15C is disposed on the inner peripheral side of the coil portion 15A, when the diameter of the coil portion 15A progresses, the friction generated in the resistor 15C accordingly. Strength increases.

  Accordingly, it is necessary to appropriately select whether the resistor 15C is disposed on the outer peripheral side or the inner peripheral side of the coil portion 15A in accordance with the amplitude of chattering, that is, the operating angle when chattering occurs.

(Third embodiment)
This embodiment is a modification of the second embodiment. That is, in the resistor 15C according to the second embodiment, the cylindrical resistor 15C provided with the slit portion 15D is disposed on the inner peripheral side of the coil portion 15A, but this embodiment is as shown in FIG. Further, a resistor 15C wound in a spiral shape (spring shape) is disposed on the inner peripheral side of the coil portion 15A.

  Accordingly, in the present embodiment, when the diameter of the coil portion 15A is reduced, the resistor 15C is also reduced in diameter, so that the resistors 15C are also in sliding contact with each other at the portion where the resistor 15C overlaps. Therefore, in addition to the friction generated at the sliding contact portion between the resistor 15C and the coil portion 15A, the resistor 15C itself also generates friction, so that the kinetic energy can be more reliably converted into the heat energy, and the chattering is surely attenuated. be able to.

(Fourth embodiment)
This embodiment is a modification of the third embodiment. That is, in the third embodiment, the spiral resistor 15C is disposed on the inner peripheral side of the coil portion 15A. However, in the present embodiment, as shown in FIG. The body 15C is disposed on the inner peripheral side of the coil portion 15A.

That is, in this embodiment, another spring is combined as a resistor 15 </ b> C in the coil portion 15 </ b> A of the spring 15.
(Fifth embodiment)
In the present embodiment, as shown in FIG. 8, the frictional heat generated with the deformation of the spring 15 is increased by increasing the contact pressure of the wire in the coil portion 15 </ b> A, and the valve generated with the displacement of the valve body 11. The kinetic energy of the body 11 is converted into thermal energy and absorbed in the atmosphere.

That is, in this embodiment, coil part 15A itself functions as an attenuation part which converts the kinetic energy of valve body 11 into thermal energy and absorbs it in the thermal energy atmosphere.
In addition, the magnitude | size of "the contact | adherence pressure of the wire in 15 A of coil parts" can be enlarged if the initial tension at the time of coiling which shape | molds 15 A of coil parts is enlarged.

  Incidentally, FIG. 9 is a graph obtained by measuring acceleration generated in the valve body 11 in three types of exhaust valves 10 having different initial tensions during coiling. And as shown in FIG. 9, the initial tension at the time of coiling is large, and the contact pressure of the wire in the coil portion 15A increases, so that the acceleration generated in the valve body 11, that is, the chattering of the valve body 11 can be effectively attenuated.

(Sixth embodiment)
In the exhaust valve 10 according to the above-described embodiment, the spring 15 is disposed outside the exhaust passage, that is, the housing 1D. However, in this embodiment, the spring 15 is disposed in the housing 1D as shown in FIG. This is an example.

  FIG. 10 shows the spring 15 in which the resistor 15C is disposed on the inner peripheral side of the coil portion 15A, that is, the spring 15 according to the second embodiment. However, the present embodiment is not limited to this. The spring 15 according to other embodiments may be used.

(Other embodiments)
Although the resistor 15C according to the first and second embodiments has the friction material 15F made of metal mesh, the present invention is not limited to this. For example, the friction material 15F is abolished. Alternatively, the friction material 15F may be made of something other than a metal mesh.

  In the above-described embodiment, the friction damper is a kind of friction damper using the frictional force between the resistor 15C and the spring 15. However, the present invention is not limited to this, for example, the viscosity of a liquid such as oil. You may comprise a damping | damping part with the viscous damper using resistance.

  Further, the present invention is not limited to the above-described embodiment as long as it matches the gist of the invention described in the claims.

DESCRIPTION OF SYMBOLS 1 ... Exhaust heat recovery apparatus 1A ... Heat exchanger 1B ... Exhaust path 1C ... Exhaust path 1D ... Housing 3 ... Internal combustion engine 5 ... Exhaust pipe 7 ... Silencer 10 ... Exhaust valve 11 ... Valve body 13 ... Drive shaft 13B ... Bearing part 13A ... Shaft casing 15 ... Spring 15A ... Coil part 15B ... Hook part 15C ... Resistor 15E ... Spring material 15F ... Friction material 15D ... Slit part 17 ... Actuator

Claims (12)

An exhaust valve for controlling the flow of exhaust discharged from an internal combustion engine,
A valve body disposed displaceably in the exhaust flow path;
An exhaust valve, comprising: an attenuation portion that converts kinetic energy of the valve body generated by displacement of the valve body into heat energy and absorbs it. A spring that acts on the valve body with an elastic force in a direction to close the flow path;
2. The exhaust valve according to claim 1, wherein the damping portion absorbs the kinetic energy by frictional heat generated along with deformation of the spring. The attenuation portion includes a resistor that is slidably contacted with the spring,
3. The exhaust valve according to claim 2, wherein the frictional heat is generated by sliding the spring against the resistor in accordance with elastic deformation of the spring.   The exhaust valve according to claim 3, wherein the resistor has a spring material that can be elastically deformed in accordance with the deformation of the spring. The spring is a torsion coil spring having a coil portion in which a wire is wound in a coil shape,
The exhaust valve according to claim 3 or 4, wherein the resistor is in contact with an outer peripheral side or an inner peripheral side of the coil portion. The resistor is a cylindrical body disposed on the outer peripheral side of the coil portion,
Furthermore, the said resistor is provided with the slit part extended in the direction parallel to the axial direction of the said coil part, and making the said resistor discontinuous in the circumferential direction. Exhaust valve. Applied to an exhaust valve that controls the flow of exhaust discharged from an internal combustion engine,
A spring that applies an elastic force to a valve element that is displaceably disposed in the exhaust flow path,
A spring body that is elastically displaced in conjunction with the displacement of the valve body;
A spring comprising: a damping portion that converts the kinetic energy of the valve body generated by the displacement of the valve body into thermal energy and absorbs it.   The spring according to claim 7, wherein the damping part absorbs the kinetic energy by frictional heat generated with the deformation of the spring body. The attenuation portion includes a resistor that is slidably contacted with the spring body,
The spring according to claim 8, wherein the frictional heat is generated by sliding the spring body in contact with the resistor in accordance with elastic deformation of the spring body.   The spring according to claim 9, wherein the resistor includes a spring material that can be elastically deformed with deformation of the spring body. The spring body is a coil portion of a torsion coil spring,
The spring according to claim 9 or 10, wherein the resistor is in contact with an outer peripheral side or an inner peripheral side of the spring body. The resistor is a cylindrical body disposed on the outer peripheral side of the spring body,
Furthermore, the said resistor is provided with the slit part extended in the direction parallel to the axial direction of the said spring main body, and making the said resistor discontinuous in the circumferential direction. Spring.