JP2012036828A - Mounting structure of heat shield material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hold a heat shield material by predetermined pressing force with a simple construction.SOLUTION: The heat shield material includes mounting holes and is mounted to an exhaust guide member by bolts with spacers inserted in the mounting holes. The boles are fastened to the exhaust guide member with prescribed torque. The spacers are pressed for a predetermined amount by the fastening force of the bolts and the spacers are deformed by the pressing force so that the bolts press the heat shield material by the predetermined pressing force. Therefore, the bolts are fastened with the predetermined torque, and the heat shield material is held by the predetermined force and is surely mounted to the exhaust guide member without being affected by thermal deformation of the exhaust guide member.

Description

  The present invention relates to a heat shield mounting structure that is mounted on an internal combustion engine or the like.

  A heat shield is attached to an exhaust guide member (exhaust manifold) that guides exhaust from an exhaust port of a normal vehicle internal combustion engine so that heat generated from the exhaust guide member does not affect other devices. Yes.

  On the other hand, the exhaust guide member has a large temperature difference between the cold time and the warm time, and the interval between the screw holes fixing the heat shield is changed by thermal expansion (including thermal contraction; the same applies hereinafter). And since the heat shielding material and the exhaust guide member are not the same in temperature change and have different thermal expansion coefficients, if the heat shield material is firmly fixed to the exhaust guide member, stress is generated due to the difference in thermal expansion, Cracks and breaks may occur in the heat shield. Therefore, the heat shielding material is provided with play between the mounting bolts and absorbs the difference in displacement due to thermal expansion by the play of the mounting portion.

  Patent Document 1 describes an invention in which a spring member, a friction member having an appropriate frictional force, and the like are provided in a mounting hole for a heat shield, thereby forming play and holding the heat shield with a predetermined pressing force. Yes.

  In addition, the heat shield is constantly vibrated during traveling, and if it is not securely attached by screws, it may be vibrated and generate noise, or the mounting screws may loosen and fall off. Therefore, the screw needs to be securely fastened to the exhaust guide member.

Japanese Patent Laid-Open No. 11-50842

  However, if a friction member or a holding member using a spring is attached to the hole formed in the heat shielding material, and the heat shielding material is fixed to the holding member through bolts, the number of parts increases or installation takes time. Cost could increase.

  Even if the bolt is fastened to the screw hole with the specified torque, and the heat shield is directly fixed, the heat shield is thin and appropriate torque management is difficult. It was difficult to allow movement of the heat shield due to expansion.

  The present invention has been made in view of the above problems, and provides a heat shield mounting structure that can reduce the number of components, is low in cost, and can reliably hold the heat shield with a predetermined pressing force. Objective.

In the present invention, the heat shield mounting structure is configured as follows.
The heat shielding material is attached to the mounting member by passing a bolt through a through hole formed in the heat shielding material and fastening the bolt to the mounting screw hole. A spacer is provided between the bolt and the mounting member. The spacer has a shape in which a predetermined amount of gap is formed on the outer periphery of the spacer when the spacer is inserted into the through hole.

  In addition, when the bolt is tightened to the mounting screw hole with the specified torque, the bolt is fastened to the mounting screw hole with the desired tightening torque via the spacer, and the heat shield is pressed with the desired pressure by the bolt. It is formed to be.

  The spacer is formed such that when the bolt is tightened into the mounting screw hole with a predetermined torque, the spacer is deformed by a predetermined amount so that the distance between the bolt and the mounting member is an interval for pressing the heat shield with a predetermined pressure. .

  By tightening the bolt with a specified torque, the heat shield is directly pressed by the bolt with a predetermined pressing force. Therefore, the heat shield can be pressed with a predetermined pressing force with a small number of parts. The bolt tightening operation can be easily performed.

It is sectional drawing which shows the attachment structure of the heat-shielding material concerning this invention. It is sectional drawing which shows the attachment structure of the heat shield shown in FIG. It is a disassembled sectional view which shows the attachment structure of the heat shield shown in FIG. It is a front view which shows a heat shield.

  An embodiment of a heat shield mounting structure according to the present invention will be described.

  FIG. 4 shows the heat shielding material 10. The heat shield 10 is attached to an exhaust guide member (exhaust manifold) 30 (see FIG. 1) as an attachment member. The exhaust guide member 30 is attached to an exhaust port of an internal combustion engine (not shown), and guides exhaust exhausted from the internal combustion engine to an exhaust pipe (not shown). The internal combustion engine is, for example, a diesel engine.

  In FIG. 1, the attachment structure of the heat-insulating material 10 is shown. As shown in FIG. 1, the heat shield 10 is attached to the exhaust guide member 30 by bolts 12. A mounting hole 14 is formed in the heat shield 10, and a spacer 16 is inserted into the mounting hole 14. The bolt 12 passes through the spacer 16 and is fixed to the mounting screw hole 34 of the exhaust guide member 30.

  The heat shielding material 10 is formed from a member having a heat insulating action, and has a predetermined thickness b (see FIG. 3). The mounting hole 14 is provided in advance in the heat shield 10 at a position corresponding to the mounting screw hole 34 by pressing or the like. The mounting hole 14 is basically formed in an oval shape, and is formed so as to provide a predetermined gap in a predetermined direction with the spacer 16. That is, the mounting hole 14 is exhausted via the spacer 16, that is, the bolt 12, between any of the mounting holes 14 when a thermal expansion or contraction action is exerted on the exhaust guide member 30 as the temperature changes. The guide member 30 is formed so as not to be pulled or compressed.

  The bolt 12 is a flange bolt and has a flange 18 at the head. The bolts 12 are formed with a predetermined strength, and all the bolts 12 are formed so that the prescribed torque is the same.

  The exhaust guide member 30 is formed with a pedestal 32 raised from the periphery, and an attachment screw hole 34 is formed near the center of the pedestal 32.

  The spacer 16 is made of a material having a predetermined hardness, and has an outer diameter having a predetermined play between the inner hole 20 that penetrates the shaft portion of the bolt 12 and the mounting hole 14, as shown in FIG. It is formed with a predetermined thickness a which will be described later.

  The thickness a of the spacer 16 is set to be larger than the thickness b of the heat shield 10 by a predetermined amount. The bolt 12 is passed through the spacer 16, and the bolt 12 is tightened in the mounting screw hole 34 until the bolt 12 contacts the spacer 16. Then, as shown in FIG. 2, the heat shield 10 is attached between the flange 18 of the bolt 12 and the base 32 with a predetermined gap in the thickness direction.

  Next, when the bolt 12 is further rotated from the above state and tightened to a specified torque, the spacer 16 is pressed by the axial pressure from the bolt 12, and the thickness is reduced by a predetermined amount. The predetermined amount by which the thickness of the spacer 16 is reduced is a value set so that a predetermined pressing force is applied to the heat shield 10 via the flange 18 of the bolt 12 when the bolt 12 is fastened with a specified torque.

  When the heat shield 10 is pressed with a predetermined pressing force, the flange 18 slightly deforms the heat shield 10 in the thickness direction to securely hold the heat shield 10 and the exhaust guide member 30 is thermally expanded (thermal contraction). If the distance between the mounting screw holes 34 changes, the bolt 12, that is, the mounting screw hole 34 of the exhaust guide member 30, does not restrain the heat shielding material 10. It is set to be movable. For example, about 90% of the axial force generated in the bolt 12 is applied to the spacer 16 and the remaining 10% is applied to the heat shield 10.

  Next, the effect | action of the attachment structure of the heat-shielding material 10 is demonstrated.

  The spacer 16 is inserted into the mounting hole 14, the bolt 12 is passed through the spacer 16, and the bolt 12 is fastened to the mounting screw hole 34 with a specified torque. Then, the spacer 16 is pressed by a predetermined amount by the bolt 12, and the distance between the flange 18 and the upper surface of the pedestal 32 becomes c as shown in FIG. This state is a state where a predetermined axial force is applied to the bolt 12 via the spacer 16 and the heat shield 10 is pressed from the flange 18 with a predetermined pressing force.

  As a result, the bolt 12 is fastened to the mounting screw hole 34 with a specified torque, and the heat shield 10 is securely held by the bolt 12 via the flange 18 with a predetermined pressing force. Therefore, when the heat shield 10 does not flutter due to vibration during traveling or the bolt 12 does not loosen and the exhaust guide member 30 is thermally expanded due to a temperature change, the heat shield 10 and the flange 18 Relative movement occurs between them, and the heat shield 10 is not subjected to stress due to thermal expansion of the exhaust guide member 30.

  Since the mounting structure of the heat shield 10 is configured as described above, the heat shield 10 can be securely attached to the exhaust guide member 30 by fastening the bolts 12 with a specified torque. Further, when the thickness or material of the heat shield 10 is changed, when the bolt 12 is fastened with a specified torque, a material that is deformed by a predetermined amount so that a predetermined pressing force is applied to the heat shield 10, A spacer 16 having a thickness or the like is selected.

  Therefore, the spacer 16 can be easily attached regardless of the type of the heat shielding material 10 by appropriately selecting the spacer 16. Moreover, since the predetermined attachment hole 22 should just be formed in the heat shield material 10 by press work etc., the heat shield material 10 can be provided at low cost. Since all the bolts 12 should be fastened with a predetermined torque, the bolts 12 can be easily tightened.

  In the above example, the spacer 16 is pressed and deformed so that the distance between the flange 18 and the upper surface of the pedestal 32 becomes a predetermined distance. However, the present invention is not limited thereto, and when the bolt 12 is tightened with a prescribed torque, the spacer You may comprise so that predetermined | prescribed pressing force may be given to the heat-shielding material 10, without deform | transforming 16. Further, the member to be attached is not limited to the heat shielding material. Furthermore, it does not have to be a flange bolt.

  The present invention is used when a heat shield is attached to an internal combustion engine.

DESCRIPTION OF SYMBOLS 10 ... Heat insulation material 12 ... Bolt 14 ... Mounting hole 16 ... Spacer 18 ... Flange 20 ... Inner hole 22 ... Mounting hole 30 ... Exhaust guide member 32 ... Base 34 ... Hole

Claims (3)

A mounting structure for a heat shield that passes a bolt through a mounting hole formed in a heat shield, and fastens the bolt to a mounting screw hole provided in a mounting member to attach the heat shield to the mounting member.
A spacer is provided between the bolt and the mounting member,
When the bolt is tightened to the mounting screw hole with a predetermined torque, a predetermined axial force is generated on the bolt via the spacer, and a desired pressing force is applied to the heat shield via the bolt. An installation structure for a heat shield, wherein the heat shield is configured to be held at a predetermined pressure by the bolt.   When the bolt is tightened in the mounting screw hole with a prescribed torque, the spacer is pressed and deformed by a predetermined amount, and the space between the bolt and the mounting member presses the heat shield with a predetermined pressure due to the pressing deformation of the spacer. The heat shielding material mounting structure according to claim 1, wherein an interval of the heat shielding material is provided.   3. The heat shield mounting structure according to claim 1, wherein the mounting hole has a shape having a predetermined gap with respect to the spacer inserted into the mounting hole.

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