Mounting structure for an engine mount

Abstract

A frame-side pin hole is formed on an inner surface, which is a vertical surface of a front side frame that is part of a vehicle frame and is in contact with a support surface of an engine mount. An engine mount-side pin hole is formed in the support surface, which is a vertical surface of the engine mount and is in contact with the front side frame (the inner surface). Furthermore, a displacement prevention pin is inserted through the frame-side pin hole and the engine mount-side pin hole.

Description

TECHNICAL FIELD

[0001] The present invention relates to a structure for mounting an engine mount, and more particularly to a structure for mounting an engine mount to a vehicle frame by means of bolts. BACKGROUND

[0002] Typically, an engine mount is mounted on a vehicle. The engine mount is a part provided between an internal combustion engine and a vehicle body to connect them. The engine mount serves to prevent the transmission of engine vibrations to the vehicle body (provides a vibration-preventing / damping function) and to support the engine weight (provides a load-bearing function) while regulating displacement of the internal combustion engine due to torque reaction or force input from the road surface.

[0003] The engine mount is typically attached to the vehicle frame by bolts. Specifically, the engine mount includes a bracket serving as a mounting member, and the bracket and the vehicle frame are mutually bolted. For example, JP 2011-098645 A discloses a structure for mounting the engine mount to the vehicle frame using multiple bolts. JP 2009-023597 A further discloses a structure for mounting the engine mount to the vehicle frame using three bolts that form a triangle when the bolt positions are connected accordingly with a straight line, to improve the mounting strength for the internal combustion engine.

[0004] To attach the engine mount to the vehicle frame with bolts, the bolts are inserted through bolt holes formed in the vehicle frame and in the engine mount bracket and tightened with nuts. Fig. 9 is a sectional view showing a state in which the vehicle frame and the engine mount bracket are tightened by a bolt.

[0005] The screw holes in the vehicle frame and the bracket have a diameter slightly larger than the screw diameter, so that the screws can be inserted with tolerance. Therefore, the Fig. 9, a clearance is formed between the outer surface of the screw and the inner surfaces of the screw holes formed in the vehicle frame and the bracket.

[0006] In such a state, when a force exceeding the maximum static friction force between the vehicle frame and the bracket acts in a direction parallel to the contact surfaces of the vehicle frame and the bracket, the vehicle frame and the bracket will move (displace) relatively in a direction parallel to the contact surfaces between them. This displacement in the direction along the contact surfaces between the bolted objects is called slippage.

[0007] In particular, as in Fig. As shown in Figure 9, when the bolt is inserted and fastened through the bolt hole formed in the vertical surface of the vehicle frame and the bolt hole formed in the vertical surface of the bracket, a large force is applied to the vehicle frame and the engine mount due to a force input from the road surface, particularly in a vertical direction (i.e., the direction parallel to the contact surface). Thus, when the bolt is tightened horizontally, slippage between the vehicle frame and the bracket is particularly likely to occur.

[0008] The occurrence of slippage between the vehicle frame and the bracket leads to slippage between the vehicle frame or bracket and the bolt or nut, generating torque on the seating surface of the bolt or nut in a bolt-loosening direction. Thus, if slippage occurs repeatedly between the vehicle frame and the bracket, it will lead to a bolt loosening problem. If the bolt loosens, the attachment of the engine mount to the vehicle frame becomes insufficient, the engine mount's functions will no longer be available properly, and problems such as vibration or noise in the vehicle may occur.

[0009] From JP 2004 - 345 610 A as well as DE 26 27 382 A1, further engine mount mounting structures for mounting an engine mount to a vehicle frame by means of screws are known, whereby these documents do not discuss a displacement prevention pin in the sense of the invention.

[0010] The object of the present invention is to prevent the loosening of horizontally tightened screws for fastening an engine mount to a vehicle frame. This object is achieved by the engine mount mounting structure having the features of the independent claims 1 and 4; advantageous further developments are the subject of the dependent claims. SUMMARY

[0011] The present invention provides, according to claim 1, an engine mount mounting structure for mounting an engine mount to a vehicle frame by horizontally tightening bolts, comprising: a frame-side pin hole formed on a vertical surface of the vehicle frame in contact with the engine mount; an engine mount-side pin hole formed on a vertical surface of the engine mount in contact with the vehicle frame; and a displacement preventing pin inserted through the frame-side pin hole and the engine mount-side pin hole to prevent relative displacement between the vehicle frame and the engine mount in a direction parallel to the contact surface therebetween.

[0012] According to the above-described structure, since slippage between the vehicle frame and the engine mount is prevented by the displacement prevention pin, the occurrence of torque in a bolt-loosening direction due to the slippage can be prevented. Thus, loosening of a bolt or bolts is prevented.

[0013] Preferably, the frame-side pin hole, the motor mount-side pin hole, and the displacement prevention pin are each provided in multiples.

[0014] When a force in multiple directions is applied to the vehicle frame and the engine mount due to the force input from the road surface, if only one displacement prevention pin is provided, slippage may occur at the contact surface between the vehicle frame and the engine mount in a rotational direction around the center of the displacement prevention pin; however, if multiple displacement prevention pins are provided, the slippage in the rotational direction can be prevented.

[0015] Preferably, a spacer is arranged between a head bearing surface of the screw and a nut to be combined with the screw.

[0016] If the distance between the head bearing surface of the bolt and the nut is larger, axial elastic deformation (a slight deflection) of the bolt is easily caused. The influence of slippage between the fastened objects can be absorbed by this elastic deformation of the bolt, preventing the occurrence of slippage between the bolt or nut and the fastened objects and preventing the occurrence of loosening torque. Therefore, providing a spacer between the head bearing surface of the bolt and the nut increases the distance between the head bearing surface of the bolt and the nut, allowing the bolt to more easily undergo elastic axial deformation. Thus, loosening of the bolt due to slippage can be prevented even if slippage occurs between the vehicle frame and the engine mount.

[0017] The present invention provides, according to claim 4, an engine mount mounting structure for mounting an engine mount to a vehicle frame by horizontally tightening bolts, comprising: a pin hole formed on one of a vertical surface of the vehicle frame in contact with the engine mount and a vertical surface of the engine mount in contact with the vehicle frame; and a displacement preventing pin integrally formed on the other of the vertical surface of the vehicle frame in contact with the engine mount and the vertical surface of the engine mount in contact with the vehicle frame, and inserted through the pin hole to prevent relative displacement between the vehicle frame and the engine mount in a direction parallel to the contact surface therebetween. Advantageous effects of the invention

[0018] The present invention can prevent the loosening of bolts tightened horizontally to mount the engine mount to the vehicle frame. SHORT DESCRIPTION OF THE DRAWING

[0019] An embodiment(s) of the present invention will be described below with reference to the drawings, in which: Fig. 1 is a perspective view of a mounting structure for an engine mount according to an embodiment; Fig. 2 an XZ sectional view through a position of a screw; Fig. 3 is an XZ sectional view through a position of a displacement preventing pin; Fig. 4 is a view showing a modification of the displacement preventing pin; Fig. 5 is an XZ sectional view showing a position where a plurality of displacement preventing pins are formed; Fig. 6 is a side view of a vehicle frame in which a plurality of displacement preventing pins are formed; Fig. 7 is a view showing a state in which slippage generated at the bearing surfaces of the bolt and the nut is prevented by the elastic deformation of the bolt; Fig. 8 is an XZ sectional view through a position of screws in which a spacer is provided in addition to the displacement preventing pins; and Fig. 9 is a view showing a state where a clearance is formed between the inner surface of the screw hole and the outer surface of the screw. DESCRIPTION OF EMBODIMENTS

[0020] Fig. Figure 1 shows a perspective view of a mounting structure for an engine mount according to one embodiment. In this embodiment, an engine mount 12 is mounted on a front side frame 10, which is part of a vehicle frame. In practice, a plurality of engine mounts 12 are mounted on the right and left front side frames. Fig. However, Fig. 1 shows only one engine mount 12. In the drawings attached to this specification, a width direction, a longitudinal direction, and a vertical direction of a vehicle body are defined as X-axis, Y-axis (forward direction is equal to the positive direction of the Y-axis), and Z-axis.

[0021] The front side frame 10 is a metal frame extending in the Y-axis direction, i.e., the longitudinal direction of the vehicle. Its XZ cross-section has a substantially rectangular outer shape, and this metal frame has a hollow interior. Therefore, the front side frame 10 has a vertical outer surface 10a and a vertical inner surface 10b.

[0022] The engine mount 12 has a bracket with a main body portion 12a and a mounting surface 12b, which is a vertical surface made of metal. The bracket is a member for mounting the engine mount 12 to the front side frame 10. As shown in Fig. 1, the support surface 12b is attached to the front side frame 10 by means of a plurality (four in this embodiment) of screws 14 to fix the engine mount 12 to the front side frame 10.

[0023] Fig. 2 shows an XZ sectional view of the front side frame 10 and the engine mount 12 through a position of the screws 14.

[0024] As in Fig. As shown in Figure 2, the outer surface 10a of the front side frame 10 has a plurality of screw holes 20a. Similarly, the inner surface 10b has a plurality of screw holes 20b, and the support surface 12b has a plurality of screw holes 22. The respective screws 14 are inserted through these screw holes 20a, 20b, and 22 and tightened by means of nuts 24. Reference numeral 26 in Fig. 2 shows a washer.

[0025] The screw holes 20a, 20b, and 22 are formed in the outer surface 10a, the inner surface 10b, and the support surface 12b, which are vertical surfaces, and the screws 14 inserted through them are tightened horizontally. That is, the respective screws 14 are fastened in a state in which they extend horizontally.

[0026] As in Fig. 2, the screw holes 20a, 20b and 22 have a diameter larger than that of the screws 14, so that there is a clearance between the inner surfaces of the screw holes 20a, 20b and 22 and the outer surfaces of the screws 14.

[0027] Referring again to Fig. 1, the engine mount mounting structure according to this embodiment has a displacement preventing pin 16 for preventing relative displacement (ie, "slip") in a direction parallel to the contact surface (YZ surface) between the front side mount 10 and the support surface 12b.

[0028] Fig. 3 shows an XZ sectional view of the front side bracket 10 and the engine bracket 12 through a position of the displacement preventing pin 16.

[0029] As in Fig. As shown in Figure 3, a frame-side pin hole 30 is formed on the inner surface 10b, which is a vertical surface of the front side frame 10 and in contact with the support surface 12b. Furthermore, a motor bracket-side pin hole 32 is formed in the support surface 12b, which is a vertical surface of the motor bracket 12 and in contact with the front side frame 10 (the inner surface 10b). The YZ cross-sections of the frame-side pin hole 30 and the motor bracket-side pin hole 32 are round.

[0030] The displacement prevention pin 16 is inserted through the frame-side pin hole 30 and the motor mount-side pin hole 32. The YZ cross-section of the displacement prevention pin 16 is also round. The displacement prevention pin 16 prevents the front side frame 10 and the support surface 12b from moving relative to each other toward the contact surface. Thus, slippage between them is prevented.

[0031] In order to prevent slippage between the front side frame 10 and the support surface 12b, the displacement prevention pin 16 is preferably press-fitted or shrink-fitted into the frame-side pin hole 30 and the engine mount-side pin hole 32. In other words, the distance between the outer surface of the displacement prevention pin 16 and the inner surfaces of the frame-side pin hole 30 and the engine mount-side pin hole 32 is preferably zero (0).

[0032] However, considering a distance of the engine mount 12 from the front side frame 10, a slight clearance may be allowed between the inner surfaces of the frame-side pin hole 30 and the engine mount-side pin hole 32 and the outer surface of the displacement prevention pin 16. In this case, the clearance is smaller than the clearance between the inner surfaces of the screw holes 20a, 20b, and 22 and the outer surface of the screw 14, so that the slippage between the front side frame 10 and the support surface 12 can be prevented more effectively than in the case where the displacement prevention pin 16 is not used.

[0033] Fig. 4 shows a modification of the displacement prevention pin 16. As in Fig. As shown in Figure 4, a displacement prevention pin 16' is formed integrally with the support surface 12b and may be configured to protrude from the support surface 12b to penetrate the inner surface 10b. The displacement prevention pin 16' may further be inserted through the frame-side pin hole 30. Alternatively, the displacement prevention pin 16' may be formed integrally with the inner surface 10b, protruding from the inner surface 10b toward the support surface 12b. The displacement prevention pin 16' may be inserted through the motor bracket-side pin hole 32.

[0034] The displacement prevention pin 16 may be provided multiple times. Fig. 5 shows an XZ sectional view of the front side frame 10 and the engine mount 12, in which two displacement preventing pins 16 are provided.

[0035] When a plurality of displacement preventing pins 16 are provided, the inner surface 10b of the front side frame 10 has a plurality of frame-side pin holes 30, and the support surface 12b has a plurality of engine support-side pin holes 32. In addition, the respective displacement preventing pins 16 are inserted through the frame-side pin holes 30 and the engine support-side pin holes 32, respectively.

[0036] Fig. 6 shows a side view (viewed in the positive direction starting from the negative direction of the X-direction in Fig. 1) of the front side frame 10, on which the engine mount 12 is mounted. Fig. 6 shows a plurality of screws 14 (and washers 26) attached to the outer surface 10. Fig. 6 also shows positions of two displacement preventing pins 16A and 16B inserted through two frame-side pin holes 30 formed in the inner surface 10b.

[0037] When a force is applied in only one direction (for example, a vertical direction) to the front side frame 10 and the support surface 12b, slippage between the front side frame 10 and the support surface 12b can be prevented by only one displacement prevention pin 16. However, when only one displacement prevention pin 16 (such as the displacement prevention pin 16A in this illustration) is provided, and a force is applied to the front side frame 10 and the support surface 12b in multiple directions and parallel to the contact surface between them, slippage in the rotational direction with the displacement prevention pin 16A as the center point at the contact surface between the front side frame 10 and the support surface 12b, as shown in Fig. 6 shown.

[0038] The provision of a plurality of displacement prevention pins 16 can prevent the above-described slippage in the rotational direction. For example, as shown in Fig. 6, the slip in the rotational direction is prevented by the displacement prevention pin 16A as the center point by means of the displacement prevention pin 16B. In addition, the slip in the rotational direction can also be prevented by the displacement prevention pin 16A with the displacement prevention pin 16B as the center point.

[0039] As described above, slippage between the front side frame 10 and the support surface 12b is prevented by the displacement prevention pins 16. Thus, slippage between the front side frame 10 and the support surface 12b, as well as between the bolts 14 or the nuts 24 for fastening them, is prevented, and a moment in the direction of loosening the bolts is reduced. Thus, the simple structure of this embodiment prevents loosening of the bolts 14 for mounting the front side frame 10 to the engine mount 12.

[0040] Furthermore, as the distance between the head bearing surface of the screw and the nut increases, the screw is unlikely to loosen even if slippage occurs between the fastened objects. This will be discussed below with reference to Fig. 7 described.

[0041] Fig. Fig. 7 is a sectional view showing a state in which the support surface 12b is fixed to the front side frame 10 by the screw 14 in the same manner as in the above-described embodiment. For example, consider a case in which slippage occurs between the front side frame 10 and the support surface 12b to move the support surface 12b relatively upward in Fig. 7. When the slippage occurs between the front side frame 10 and the support surface 12b, and the nut 24 is moved upward together with the support surface 12b, the bolt 14 elastically deforms axially (is bent), and an amount of movement of the head bearing surface of the bolt 14 (and the washer 26) with respect to the outer surface 10a is reduced.

[0042] Thus, even if slippage occurs between the front side frame 10 and the support surface 12b, the slippage between the head bearing surface of the screw 14 and the outer surface 10a is prevented by the axial elastic deformation of the screw 14; that is, the moment generated in the head bearing surface of the screw 14 is reduced.

[0043] As the distance between the head bearing surface of the screw 14 and the nut 24 increases, the screw 14 is more likely to bend or twist. Therefore, as the distance between the head bearing surface of the screw 14 and the nut 24 increases, slippage of the bearing surface of the screw 14 or the nut 24 relative to the fastened objects becomes more difficult, even if slippage occurs between the fastened objects. In other words, loosening of the screw 14 is almost impossible.

[0044] Therefore, in this embodiment, a spacer may be provided between the head bearing surface of the screw 14 and the nut 24 to be combined with the screw 14 in order to increase the distance between the head bearing surface of the screw 14 and the nut 24.

[0045] Fig. Fig. 8 shows an XZ sectional view of the front side frame 10 through a position of the screws 14, in which a spacer 40 is arranged between the head bearing surface of the screw 14 and the nut 24. The provision of the spacer 40 increases the distance D from the head bearing surface of the screw 14 to the nut 24. Even if a slight clearance is maintained between the inner surfaces of the frame-side pin hole 30 and the engine mount-side pin hole 32 as well as the outer surface of the displacement prevention pin 16 (see Fig.3), loosening of the screws 14 can be prevented because the screws 14 bend more easily even if a slight slippage is generated between the front side frame 10 and the support surface 12b.

Claims

[1] An engine mount mounting structure for mounting an engine mount (12) to a vehicle frame (10) by horizontally tightening bolts (14), comprising: a frame-side pin hole (30) formed on a vertical surface of the vehicle frame (10) in contact with the engine mount (12); an engine mount side pin hole (32) formed on a vertical surface of the engine mount (12) in contact with the vehicle frame (10); and a displacement preventing pin (16) inserted through the frame-side pin hole (30) and the engine mount-side pin hole (32) to prevent relative displacement between the vehicle frame (10) and the engine mount (12) in a direction parallel to the contact surface therebetween. [2] The engine mount mounting structure according to claim 1, wherein the frame-side pin hole (30), the engine mount side pin hole (32) and the displacement preventing pin (16) are each provided in plural numbers. [3] The engine mount mounting structure according to claim 1 or 2, wherein a spacer (40) is disposed between a head bearing surface of the bolt (14) and a nut (24) to be combined with the bolt (14). [4] An engine mount mounting structure for mounting an engine mount (12) to a vehicle frame (10) by horizontally tightening bolts (14), comprising: a pin hole (30, 32) formed on one of a vertical surface of the vehicle frame (10) in contact with the engine mount (12) and a vertical surface of the engine mount (12) in contact with the vehicle frame (10); and a displacement preventing pin (16) which is integrally formed on the other of the vertical surface of the vehicle frame (10) in contact with the engine mount (12) and the vertical surface of the engine mount (12) in contact with the vehicle frame (10), and which is inserted through the pin hole (30, 32) to prevent relative displacement between the vehicle frame (10) and the engine mount (12) in a direction parallel to the contact surface therebetween.

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