JP2013124714A - Fixing member of control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing member of a control device capable of suppressing vibration of an engine from being transmitted.SOLUTION: The fixing member (20) of the control device for fixing the control device (10) to the engine (1) is interposed between the engine (1) and the control device (10) and is mounted on the engine via a vibration proof material (30) for damping vibration by elastic deformation. The fixing member further includes a mass body (41) supported by an elastic member (42).

Description

  The present invention relates to a fixing member of a control device mounted on a vehicle engine.

  Conventionally, a control device such as a control device (ECU) for controlling a vehicle engine is fixed to the engine body. The control device is generally composed of precision electronic components.

  When the control device is fixed to the engine, vibrations of the engine may affect the electronic components, and it is necessary to take measures to prevent this. In order not to transmit engine vibration to the control device, it is common to fix the control device to the engine via a vibration isolating material such as rubber. In addition, in order to prevent various vibrations generated by the engine, there is also known one in which vibration materials are multiplexed (see Patent Document 1).

JP 2000-38941 A

  Anti-vibration materials such as rubber alleviate vibration transmission by elastically deforming against vibration, but vibration-proof materials have natural frequencies, and transmit vibrations by resonance near natural frequencies. It has the characteristic that it ends up. Although the natural frequency can be changed somewhat by changing the shape of the vibration isolator, it has not been able to cope with a wide range of frequencies.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a fixing member for a control device that can suppress transmission of engine vibration to a control device fixed to the engine. .

  The present invention is a fixing member of a control device that is interposed between an engine and a control device and fixes the control device to the engine, and is attached to the engine via a vibration isolating material that attenuates vibration by elastic deformation. And a mass body supported by the elastic member.

According to the present invention,
Since the fixed member fixed to the engine via the vibration isolator is further provided with a mass body supported by the elastic member, the vibration of the engine is caused not only by the vibration isolator but also by the action of the mass body and the elastic body. It is attenuated and the transmission of engine vibration to the control device is suppressed.

1 is a perspective view of an engine on which an ECU according to an embodiment of the present invention is mounted. It is a perspective view of the rocker cover of the engine of the embodiment of the present invention. It is explanatory drawing of the bracket and ECU of embodiment of this invention. It is explanatory drawing of the bracket of embodiment of this invention. It is explanatory drawing which shows attenuation | damping in the bracket of embodiment of this invention. It is explanatory drawing which shows attenuation | damping of the vibration by the bracket of embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view of an engine 1 on which an ECU 10 according to an embodiment of the present invention is mounted.

  In the engine 1, vaporized fossil fuel is sent to a cylinder chamber together with air, the piston is pushed down by compressing the fuel, and the movement of the piston is output as rotational energy.

  The engine 1 is provided with a rocker cover 2 that covers components of the engine head. An engine control unit (ECU) 10 that controls the operation of the engine 1 is mounted on the top of the rocker cover 2.

  The ECU 10 determines the fuel injection amount, the fuel injection timing, etc. based on various sensors provided in the engine 1 and information such as operation instructions of the engine 1 sent from an operator (for example, accelerator pedal opening when mounted on a vehicle). Control is performed to control the rotational operation of the engine 1. A command signal is transmitted to and received from the ECU 10 via the harness 3 that is electrically connected to each sensor and each part.

  FIG. 2 is a perspective view of the rocker cover 2 of the engine 1 on which the ECU 10 of this embodiment is mounted.

  The ECU 10 is mounted on the rocker cover 2 via a bracket 20 attached to the rocker cover 2 of the engine 1.

  The engine 1 outputs rotational energy by pushing down a piston by the explosion of fossil fuel, and vibration is generated.

  The ECU 10 is equipped with precise electronic components, and it is not desirable that vibrations of the engine 1 be directly transmitted. Therefore, the ECU 10 is not directly attached to the engine 1, but the ECU 10 is fixed to the bracket 20 attached to the engine 1 via the vibration isolator 30 made of an elastic member such as rubber. This vibration isolator 30 can attenuate the vibration of the engine 1 and can attenuate the vibration of the engine 1 transmitted to the ECU 10.

  On the other hand, in the vibration isolator 30 made of an elastic member such as rubber, a natural mass frequency exists in the spring-mass system constituted by the ECU 10 and the vibration isolator 30. When the vibration frequency of the engine 1 is the same as or close to the natural vibration frequency, resonance is caused and vibration larger than the vibration of the engine 1 is generated in the ECU 10.

  Therefore, in the embodiment of the present invention, the configuration near the natural frequency of the elastic member is attenuated by the following configuration.

  FIG. 3 is an explanatory diagram of the bracket 20 and the ECU 10 according to the embodiment of the present invention, and shows a cross-sectional view taken along the line AA in FIG. FIG. 4 is a top view of the bracket 20 according to the embodiment of the present invention. Hereinafter, the bracket 20 will be described with reference to FIGS. 2, 3, and 4.

  The bracket 20 is a flat member that is interposed between the engine 1 and the ECU 10 and is a fixing member that supports the ECU on the rocker cover 2 at the top of the engine 1.

  The bracket 20 is attached to the rocker cover 2 via a vibration isolator 30. The outer shape of the bracket 20 is substantially rectangular, and has a hollow portion in a rectangular shape inside thereof. That is, the bracket 20 has a frame shape as a whole.

  Anti-vibration material fixing holes 22 for attaching the anti-vibration material 30 are provided at four locations around the bracket 20. The vibration isolator 30 includes a bolt 31 penetrating the center thereof, a metal cylindrical collar 33 into which the bolt 31 is inserted, and an elastic member 32 mounted around the collar 33. . An elastic member 32 is fitted and fixed in the vibration isolator fixing hole 22 of the bracket 20. Further, the bolt 31 of the vibration isolator 30 is fixed to the rocker cover 2. As a result, the bracket 20 is fixed to the rocker cover 2 via the vibration isolator 30, and the elastic member 32 of the vibration isolator 30 holds the bracket 20 with a constant force without being affected by the tightening force of the bolt 31. The spring coefficient of the elastic member 32 is kept constant. The elastic member 32 is made of rubber, for example.

  In addition to the vibration isolator fixing holes 22, ECU fixing holes 24 are provided at four locations around the bracket 20. The ECU 10 is fixed to the upper part of the bracket 20 by fixing the bolt 12 attached to the ECU 10 in the ECU fixing hole 24.

  In addition, a connector 4 for connecting the harness 3 is provided in the upper part of the ECU 10.

  A dynamic damper 40 including a mass body 41 and an elastic member 42 is provided inside the frame shape of the bracket 20.

  Referring to FIG. 4, a substantially rectangular mass body 41 is provided on the inner peripheral side of the frame shape of the bracket 20. The mass body 41 is, for example, a plate-like metal and has a mass corresponding to vibration characteristics as described later.

  A plurality of elastic members 42 are provided between the mass body 41 and the bracket 20, and the mass body 41 is supported by the bracket 20 via the elastic member 42. Thus, the dynamic damper 40 is configured by the mass body 41 being supported by the bracket 20 via the elastic member 42. The dynamic damper 40 constitutes a spring-mass system. The elastic member 42 is made of rubber, for example.

  In the example shown in FIG. 4, eight elastic members 42 are provided between the mass body 41 and the bracket 20, two on each of the four sides.

  The dynamic damper 40 attenuates vibration by the inertial force due to the mass of the mass body 41 and the spring coefficient of the elastic member 42. The frequency attenuated by the dynamic damper 40 can be appropriately set according to the mass of the mass body 41 and the spring coefficient of the elastic member 42.

  As described above, the bracket 20 includes the dynamic damper 40 in addition to the vibration isolator 30 so as to attenuate the vibration of the engine 1 so that the vibration of the engine 1 is not transmitted to the ECU 10.

  FIG. 5 is an explanatory diagram showing attenuation in the bracket 20 according to the embodiment of the present invention.

The example shown in FIG. 5 shows the damping in the bracket 20 when the vibration of the force represented by the expression F ₀ sin θt is applied from the engine 1.

The bracket 20 includes a vibration isolator 30 having an elastic member 32 and a dynamic damper 40 having a mass body and an elastic member. In this vibration-proof material 30, the elastic member 32 a spring constant _{K A,} has a characteristic that the damper coefficient _{C A,} supporting the entire mass _{m A} consisting of the bracket 20 and ECU 10.

The dynamic damper 40 includes a mass body 41 and an elastic member 42. The elastic member 42 has a spring constant _{K B,} the characteristic of the damper coefficient _{C B,} to support the mass _{m B} of the mass body 41.

As described above, the bracket 20 constitutes a spring-mass system having two degrees of freedom. By making the vibration damping characteristic due to the spring constant K _A and the damper coefficient C _A of the elastic member 32 different from the vibration damping characteristic due to the spring constant K _B and the damper coefficient C _B of the elastic member 42, a wide range of vibrations can be obtained. Can be attenuated.

  FIG. 6 is an explanatory diagram showing vibration attenuation by the bracket 20 according to the embodiment of the present invention.

  In FIG. 6, the horizontal axis represents the ratio (μ) of the vibration frequency to the natural frequency of the vibration isolator 30, and the vertical axis represents the vibration transmissibility (τf). When the vibration transmissibility is greater than 1, the vibration is transmitted without being attenuated, and when the vibration transmissibility is less than 1, the vibration is attenuated.

  In FIG. 6, the solid line indicates the conventional vibration transmissibility in which only the vibration isolator 30 is provided on the bracket 20, and the alternate long and short dash line indicates the vibration when the vibration isolator 30 and the dynamic damper 40 are provided on the bracket 20. Indicates the transmission rate.

  As shown in FIG. 6, when only the vibration isolator 30 is provided on the bracket 20, resonance occurs due to the natural frequency of the vibration isolator 30, so that vibration occurs near this natural frequency (the horizontal axis is near 1). The transmission rate increases. Therefore, when vibration in the vicinity of the natural frequency is applied to the bracket 20, the vibration is not attenuated, and a larger vibration is transmitted to the ECU 10 by resonance.

  On the other hand, in the embodiment of the present invention, the vibration isolator 30 and the dynamic damper 40 are provided on the bracket 20. In particular, in the embodiment of the present invention, the characteristics of the dynamic damper 40 (the mass of the mass body 41 and the elastic member) are damped so that the vibration transmissibility in the vicinity of the natural frequency of the vibration isolator 30 (the horizontal axis is about 1) is attenuated. 42 spring coefficient). With this configuration, it is possible to attenuate vibrations near the natural frequency of the vibration isolator 30 that cannot be attenuated by the vibration isolator 30.

  Thus, by providing the dynamic damper 40, it is possible to attenuate the vibrations of a wide frequency generated by the engine 1.

  As described above, in the embodiment of the present invention, the bracket 20 is interposed between the engine 1 and the ECU 10 and serves as a fixing member of the ECU that fixes the ECU 10 to the engine 1. It is further provided with a mass body 41 that is attached via a vibration isolator 30 that attenuates the vibration and supported by an elastic member 42.

  By constituting in this way, the vibration of the frequency which cannot be attenuated only by the vibration isolator 30 made of rubber, for example, can be attenuated by the characteristics of the mass body 41 supported by the elastic member 42. .

  The bracket 20 has a flat structure, and is disposed between the rocker cover 2 of the engine 1 and the ECU 10, and the mass body 41 and the elastic member 42 are disposed on the inner peripheral side of the frame-shaped bracket 20. Therefore, it is possible to improve space efficiency without taking up an extra space for mounting the ECU 10.

  Further, since the bracket 20 is provided substantially horizontally above the rocker cover 2 of the engine 1 and more specifically above the engine 1, the bracket 20 is resistant to large vertical vibrations caused by the vertical movement of the cylinder in the engine 1. Thus, vibration can be damped by the vibration isolator 30 and the dynamic damper 40.

  The dynamic damper 40 has its characteristics (the mass of the mass body 41 and the spring coefficient of the elastic member 42) set so that the vibration transmissibility near the natural frequency of the vibration isolator 30 is attenuated. The vibration near the natural frequency of the vibration isolating material 30 that cannot be attenuated depending on the vibration material 30 can be attenuated.

  In the embodiment of the present invention described above, the elastic member 42 of the dynamic damper 40 has been described as rubber, but the present invention is not limited to this. The elastic member 42 may be configured by a spring such as a coil spring, a disc spring, or a torsion spring.

  For example, when a disc spring is used, the bracket 20 can be reduced in size and thickness as a configuration in which the mass body 41 is loaded on the bracket 20 via the disc spring.

  Further, the deformation direction of the elastic member 42 provided with the bracket 20 may be arranged in any direction. The elastic member may be configured to attenuate the vibration in the vertical direction with the elastic deformation direction of the elastic member as the vertical direction, or the vibration in the horizontal direction is attenuated with the elastic deformation direction of the elastic member as the horizontal (horizontal) direction. You may comprise.

  It goes without saying that the present invention is not limited to the above-described embodiments, and includes various modifications and improvements that can be made within the scope of the technical idea.

1 Engine 2 Rocker Cover 3 Harness 4 Connector 10 Engine Control Unit (ECU)
20 Bracket 30 Anti-vibration material 31 Bolt 32 Elastic member 33 Collar 40 Dynamic damper 41 Mass body 42 Elastic member

Claims (5)

A control device fixing member interposed between the engine and the control device and fixing the control device to the engine,
Attached to the engine via a vibration isolator that attenuates vibration by elastic deformation,
A fixing member for a control device, further comprising a mass body supported by an elastic member.   The fixing member for a control device according to claim 1, wherein the mass body is supported via the elastic member that has a substantially rectangular frame shape and is provided on an inner peripheral side of the frame shape. It has a substantially rectangular frame shape and is formed flat,
The mass body is supported via the elastic member provided on the inner peripheral side of the frame shape,
The fixing member of the control device according to claim 1, wherein the mass body is disposed between the engine and the control device. A rocker cover is provided at the top of the engine,
The individual member of the control device according to any one of claims 1 to 3, wherein the control member is attached to an upper portion of the rocker cover via the vibration isolator.   The mass of the mass body and the spring coefficient of the elastic member are set so as to attenuate vibrations near the natural frequency of the vibration isolator. A fixing member of the control device.

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