Leaf spring silencer for commercial vehicles

Abstract

A silencer (100) for a leaf spring assembly (10) for a commercial vehicle, wherein the silencer (100) comprises: an upper rubber body (110) in which a fitting hole (111) is defined into which a second leaf spring (12) can be pressed, wherein an upper surface of the upper rubber body (110) serves as a contact surface for contact with a first leaf spring (11), and a lower rubber body (120) in which a damper chamber (121) is defined, wherein a first damper projection (122) is provided and arranged on a lower surface of the lower rubber body (120) to come into contact with a third leaf spring (13).

Description

TECHNICAL FIELD

[0001] The present invention generally relates to a muffler for a leaf spring for a commercial vehicle. BACKGROUND

[0002] A commercial vehicle uses a leaf spring assembly as its rear suspension to absorb road vibrations while supporting a load applied from a cargo area. The leaf spring assembly includes a plurality of leaf springs stacked on top of each other and attached to both sides of a rear wheel axle.

[0003] Such a leaf spring device is designed to move up and down along with a rear wheel axle to absorb vibrations when the rear wheels are repeatedly compressed or decompressed depending on the road conditions while a vehicle is driving.

[0004] In this case, separate silencers are mounted at both ends of the leaf spring assembly to dampen shocks while preventing direct contact between the leaf springs.

[0005] In the following, a related configuration comprising a leaf spring device and silencer is described with reference to the attached Fig. 1 to Fig. 4 (related art).

[0006] As in Fig. 1 and Fig. 2, a leaf spring device 10 a first leaf spring 11 , a second leaf spring 12 and a third leaf spring 13 which are stacked on top of each other, with the third leaf spring 13 is arranged so that it is at the lowest point. The first to third leaf springs 11 until 13 are held together with a retaining device. At both ends of the first leaf spring 11are vehicle mounting bushings 14 and at both ends of the second leaf spring 12 silencer 20 arranged.

[0007] Here the holding device binds the first leaf spring 11 and the second leaf spring 12 so that it is convexly bent downwards and the third leaf spring 13 arranged so that it is essentially flat.

[0008] With reference to Fig. 3 and Fig. 4 each of the silencers 20 an upper rubber element 21 and a lower rubber element 22 The upper rubber element 21 and the lower rubber element 22 are on both sides of the second leaf spring 12 arranged and secured with screws 23 connected so that the upper rubber element 21 with the lower surface of the first leaf spring 11 is in contact and the lower rubber element 22from the top of the third leaf spring 13 has a predetermined distance.

[0009] Accordingly, when the commercial vehicle is unloaded in the loading area, the upper rubber element 21 of the silencer 20 on the lower surface of the first leaf spring 11 and the lower rubber element 22 remains at the specified distance from the upper surface of the third leaf spring 13 , as in Fig. 1 shown.

[0010] In contrast, when the commercial vehicle carries a load of a predetermined or greater weight in the loading area, both ends of the first and second leaf springs 11 and 12 deformed downwards by the weight of the load, and at the same time the upper rubber elements 21 the silencer 20 compressed and the lower rubber elements 22 between the second leaf spring 12 and the third leaf spring13 compressed to absorb vibrations from the road or similar and at the same time carry the weight of the load, as in Fig. 2 shown.

[0011] In addition, the upper rubber elements prevent 21 the silencer 20 the direct contact between the first leaf spring 11 and the second leaf spring 12 to avoid noise, and at the same time the lower rubber elements prevent 22 the direct contact between the second leaf spring 12 and the third leaf spring 13 to avoid noise.

[0012] The leaf spring device described above 10 is manufactured in such a way that it has a first spring constant K1 when no load is present, and a second spring constant K2 when a load of a predetermined or greater weight is present.

[0013] The second spring constant K2 can be set larger than the first spring constant K1 For example, the first spring constant K1 to 16.4 N / mm (1.67 kgf / mm) and the second spring constant K2 set to 183.4 N / mm (18.7 kgf / mm).

[0014] A point in time at which the first spring constant K1 during damping of the leaf spring device 10 to the second spring constant K2 is a point in time when the rubber elements 21 the silencer 20 are compressed and the lower rubber elements 22 between the second leaf spring 12 and the third leaf spring 13 be compressed by the weight of the load.

[0015] Such a significant change in the spring constant when transitioning from the first spring constant K1 to the second spring constant K2may inevitably cause the driver and passenger to feel a change or shock, and this may impair driving comfort.

[0016] Although the silencers 20 made of plastic or rubber for the damping process and a noise protection process, the silencers can 20 Furthermore, due to the repetition of the muffler operation, depending on the limitations of their material properties, such wear can affect the shape of the silencer. 20 change what is problematic.

[0017] If the silencer 20 excessively worn, it may also happen that the original thickness of the silencer 20 is not maintained. If the shape of the silencer 20 deformed in this way, the screws 23 which the upper rubber element 21 and the lower rubber element 22connect, be solved. As in Fig. 4, the screws can 23 due to wear in direct contact with the first leaf spring 11 which are directly above the screws 23 which causes steel contact noise and can cause the leaf spring to break, which is problematic.

[0018] The information described in this section is provided solely to enhance the understanding of the background of the invention and should not be construed as an acknowledgment or any form of suggestion that this information constitutes prior art already known to those skilled in the art. BRIEF EXPLANATION

[0019] The present invention generally relates to a silencer for a leaf spring or a leaf spring device (hereinafter referred to as a leaf spring) for a commercial vehicle (generally a motor vehicle). Particular embodiments relate to a silencer for a leaf spring for a commercial vehicle, wherein the silencer can perform a damping function and a noise-preventing function when a leaf spring moves up and down in order to improve the ride comfort of a commercial vehicle. Directional and positional designations used herein, such as "down," "up," "left," "right," etc., may refer to the installation position and orientation of the respective components, as shown, for example, in the FIGS.

[0020] The embodiments of the present invention were made in consideration of the problems encountered in the related art. Embodiments of the present invention propose a muffler for a leaf spring for a commercial vehicle, which can easily perform a damping function and a noise prevention function when a leaf spring moves up and down, and prevent wear and deformation.

[0021] According to one embodiment of the present invention, a muffler for a leaf spring for a commercial vehicle is provided. The muffler comprises: an upper rubber body or an upper rubber element (hereinafter referred to as the upper rubber body for short), in which a fitting hole or receiving hole (hereinafter referred to as the fitting hole) is defined, into which a second leaf spring can be press-fitted (e.g., press-fitted), wherein an upper surface of the upper rubber body is configured as a contact surface for contact with a first leaf spring, and a lower rubber body or a lower rubber element (hereinafter referred to as the lower rubber body for short), in which a receiving space is defined, wherein a first damper projection is provided and configured on a lower surface of the lower rubber body so that a third leaf spring can be in contact with the first damper projection.

[0022] In addition, a metal insert can be mounted or accommodated in the upper rubber body (e.g. completely enclosed by the rubber body) to support the second leaf spring, which is pressed into the fitting hole, and to reinforce the upper rubber body.

[0023] For example, a position fixing projection may be provided at a central portion of the metal insert so that a locking projection projects from an upper surface of the fitting hole into which the second leaf spring is press-fitted.

[0024] The metal insert may, for example, be provided with a plurality of coupling holes through which the metal insert is connected to the upper rubber body during vulcanization molding of the muffler.

[0025] For example, a locking hole may be provided in the second leaf spring so that the locking projection can be inserted into the locking hole in a locking manner.

[0026] The lower surface of the lower rubber body can, for example, be an inclined surface that is inclined downwards towards the first damper projection (e.g. is convexly curved downwards).

[0027] Specifically, for example, a second damper protrusion may be provided on a lower surface of the damper space of the lower rubber body to protrude upward with a convex shape at a position aligned with the first damper protrusion in an up-down direction.

[0028] In addition, for example, a partition wall with a passage may be provided in the damper space of the lower rubber body to divide the damper space into a left or first damper space and a right or second damper space in which a fluid (e.g., a liquid) is contained.

[0029] Embodiments of the present invention provide the following advantageous effects using the features described above.

[0030] On the one hand, the features according to embodiments of the present invention first enable the contact of the first damper projection with the third leaf spring and the compression and deformation of the lower rubber body in the event of impact behavior of drive wheels, thereby easily fulfilling a damper function and a noise prevention function.

[0031] Secondly, at the moment the muffler detaches from the third leaf spring due to the rebound behavior of the driving wheels, the muffler can be easily restored to the original shape due to the elastic restoring force of the damper chamber and the first and second damper projections of the lower rubber body, so that wear and deformation can be advantageously prevented.

[0032] Thirdly, since the metal insert is housed inside the upper rubber body of the muffler, the strength of the muffler can be maintained and the supporting force of the muffler to accommodate the second leaf spring can be increased.

[0033] Fourth, unlike the related technology in which the upper rubber member and the lower rubber member of the muffler are provided as separate parts and connected by bolting, the upper rubber body and the lower rubber body of the muffler are integrally formed by vulcanization molding. This makes it possible to fundamentally prevent direct contact between metal parts (e.g., the bolts and the leaf springs), thereby reducing noise and preventing leaf spring breakage. Character list

[0034] The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings in which: Fig. 1 and Fig. 2 are side views showing a configuration in the related art formed of a leaf spring device and silencers, Fig. 3 is a perspective view showing a silencer of the related art, Fig. 4 is a cross-sectional view showing the related art muffler mounted by bolting to the second leaf spring, Fig. 5 is a perspective view showing a leaf spring-mounted muffler according to an embodiment of the present invention, Fig. 6 is an exploded perspective view showing the muffler according to an embodiment of the present invention before being mounted on a leaf spring, Fig. 7 is a cross-sectional view showing the muffler according to an embodiment of the present invention mounted on a leaf spring, Fig. 8 is a cross-sectional view showing a pushing operation of the muffler according to embodiments of the present invention, Fig. 9 is a graph comparing the variations in the spring constant of the leaf spring during the impact operation of the muffler according to embodiments of the present invention with the variations in the spring constant of the leaf spring during the impact operation of a muffler of the related art, and Fig. 10 is a cross-sectional view showing a muffler according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0035] In the following, exemplary embodiments of the present invention are described in detail with reference to the accompanying drawings.

[0036] Fig. 5 is a perspective view showing a silencer mounted on a leaf spring according to embodiments of the present invention, Fig. 6 is an exploded perspective view showing a muffler according to embodiments of the present invention before being mounted on a leaf spring, and Fig. 7 is a cross-sectional view showing a leaf spring-mounted muffler according to embodiments of the present invention.

[0037] As in Fig. 5, a leaf spring device 10 a first leaf spring 11 , a second leaf spring 12 and a third leaf spring 13which are stacked on top of each other, with the third leaf spring 13 arranged so that it is at the lowest point. The first to third leaf springs 11 until 13 are held together or bound by a holding device. At both ends of the first leaf spring 11 are vehicle mounting bushings 14 arranged, and at both ends of the second leaf spring 12 are silencers 100 arranged.

[0038] Here the holding device binds the first leaf spring 11 and the second leaf spring 12 so that they are convexly bent downwards, and binds the third leaf spring 13 arranged so that it is essentially flat.

[0039] Each of the silencers 100 has an upper rubber body 110 and a lower rubber body 120 which are integrally formed by vulcanization molding. The upper rubber body 110is on the second leaf spring 12 attached, and the lower rubber body 120 is from the third leaf spring 13 so that the third leaf spring 13 with the lower rubber body 120 can come into contact.

[0040] With reference to Fig. 6 and Fig. 7 is a pass hole 111 inside the upper rubber body 110 provided so that the second leaf spring 12 into the pass hole 111 is pressed in. The upper surface of the upper rubber body 110 is a flat contact surface 112 in contact with the first leaf spring 11 provided.

[0041] In addition, a metal insert 113 inside the upper rubber body 110 taken to the second leaf spring 12 to support the fitting hole 111 is pressed in, and to ensure the strength of the upper rubber body 110to strengthen.

[0042] In a case where the silencer 100 manufactured using a vulcanization molding, if the metal insert 113 is inserted into the mold, the metal insert 113 after completion of vulcanization molding in the upper rubber body 110 of the silencer 100 be provided.

[0043] As in Fig. 6, is on the middle section of the metal insert 113 a position fixing projection 115 provided so that a locking projection 114 from the upper surface of the fitting hole 111 protrudes into which the second leaf spring 12 is pressed in.

[0044] The metal insert 113 can have a plurality of coupling holes 126 through which the metal insert 113 with the upper rubber body 110during vulcanization molding of the silencer 100 is coupled.

[0045] In addition, the second leaf spring 12 a locking hole 117 provided so that the locking projection 114 locking (e.g. form-fitting) into the locking hole 117 is used.

[0046] Accordingly, when pressing in the second leaf spring 12 into the upper rubber body 110 provided fitting hole 111 the locking projection 114 , as in Fig. 7 shown, locking into the locking hole 117 the second leaf spring 12 inserted so that the silencer 100 completely on or on the second leaf spring 12 is mounted.

[0047] Picking up the metal insert as described above 113 in the upper rubber body 110 of the silencer 100can increase the support force to increase the strength of the silencer 100 and the second leaf spring 12 to keep.

[0048] In addition, unlike the related technology in which the upper rubber element and the lower rubber element of the silencer are screwed, the upper rubber body 110 and the lower rubber body 120 of the silencer 100 According to embodiments of the present invention, the leaf springs are integrally manufactured by vulcanization molding. Accordingly, it is possible to fundamentally prevent direct contact between the metal parts (e.g., the screws (no longer required) and the leaf springs), thereby avoiding noise and preventing breakage of the leaf springs.

[0049] Inside the lower rubber body 120 of the silencer 100 is a hollow damper chamber or damping cavity 121(hereinafter referred to as damper chamber).

[0050] A first damper advantage 122 protrudes from the lower surface of the lower rubber body 120 down, and the third leaf spring 13 can be used with the first damper projection 122 come into contact.

[0051] In addition, the lower section of the lower rubber body 120 as an inclined surface 123 provided, which points downwards to the first damper projection 122 The inclined surface 123 is provided to reduce tension when a load is applied over the lower surface of the lower rubber body 120 is initiated.

[0052] In addition, a second damper projection 124 on the lower surface of the damper chamber 121 of the lower rubber body 120 provided, wherein the second damper projection 124has an upwardly extending convex shape. The second damper projection 124 is provided at a location that is aligned with the first damper projection 122 aligned or flush in a top-bottom direction. As in Fig. 7, the second damper projection remains 124 from the upper surface of the damper chamber 121 in the distance before the lower rubber body 120 is compressed to fulfill the damper function.

[0053] An operation of the muffler according to embodiments of the present invention having the above-described configuration will be described as follows.

[0054] When drive wheels (or the tires of the drive wheels) are repeatedly pushed (moved upwards) or pushed back (moved downwards) during the movement of a vehicle depending on the road conditions, the leaf spring device moves 10together with the rear wheel axle of the vehicle up or down to absorb vibrations from the road.

[0055] During the impact process, the central section of the leaf spring device moves 10 upwards to adjust the distance between the second leaf spring 12 and the third leaf spring 13 so that the forces acting on both end sections of the second leaf spring 12 mounted silencer 100 with the third leaf spring 13 come into contact to fulfill the damper function.

[0056] More precisely, as in Fig. 8, the first damper projection 122 , which is in the lower rubber body 120 each silencer 100 provided, with the upper surface of the third leaf spring 13brought into contact to perform a first damping process to absorb the shocks caused by the impact behavior. Then the lower rubber body 120 compressed and at the same time the height of the damper chamber 121 reduced so that the second damper projection 124 with the upper surface of the damper chamber 121 is brought into contact to perform a second damping action to absorb the shock.

[0057] In addition, the inclined surface 123 of the lower rubber body 120 to distribute stresses caused by the input or action of a load in response to the impact behavior, although the inclined surface 123 not in direct contact with the upper surface of the third leaf spring 13 stands.

[0058] As described above, the multi-stage damper operation of the silencer 100, including the process of the first damper projection 122 which is in contact with the third leaf spring 13 the process of the lower rubber body 120 which is compressed and deformed, the process of the second damper projection 124 which is in contact with the upper surface of the damper chamber 121 and the process of stress distribution of the inclined surface 123 , slightly or simply dampen the shock on impact.

[0059] Since the spring constant of the leaf spring device 10 from the first spring constant K1 to the second spring constant K2 which is greater than the first spring constant K1, the spring constant changes due to the processes described above along a curved section (e.g. spring constant curve), which is smoother or continuous than in the related technology, whereby the processes involve the contact of the first damper projection 122 with the third leaf spring 13 , the compression and deformation of the lower rubber body 120 , while the second damper projection 124 in contact with the upper surface of the damper chamber 121 and the stress distribution of the inclined surface 123 have.

[0060] More specifically, in the related technology, the spring constant of the leaf spring device 10 sharp or with a kink from the first spring constant K1 to the second spring constant K2 about, as in Fig. 9. In contrast, according to the embodiments of the present invention, the above-described multi-stage process or operation of the silencer 100 the spring constant along the smooth or gently curved section of the first spring constant K1 to the second spring constant K2 so that the spontaneous or local concentration of a load on the leaf spring device 10 reduced and thus the durability of the leaf spring device 10 can be improved.

[0061] In contrast, during rebound, the central section of the leaf spring device moves 10 down to adjust the distance between the second leaf spring 12 and the third leaf spring 13 to increase so that the spring force at both end sections of the second leaf spring 12 attached silencer 100 again from the third leaf spring 13are at a distance.

[0062] At the same time, the lower rubber body 120 which was compressed during the impact behavior, is easily returned to the original position by an elastic restoring force, and the spring constant of the leaf spring device 10 is determined by the second spring constant K2 to the first spring constant K1 returned.

[0063] According to a further embodiment of the present invention, as described in Fig. 10, can be found in the damper chamber 121 of the lower rubber body 120 further a partition wall 126 with a passage 125 be provided. Liquid 127 can be in a left or first damper chamber 121-1 and a right or second damper chamber 121-2 of the damper chamber 121 be included, which is caused by the partition 126 are divided or separated.

[0064] Since the liquid 127 in the damper chamber 121 of the lower rubber body 120 is contained, the liquid 127 when the lower rubber body 120 compressed and deformed, onto the left damper chamber 121-1 and the right damper chamber 121-2 distributed to perform damping.

[0065] Accordingly, a rubber band on the lower rubber body 120 concentrated load during compression and deformation of the lower rubber body 120 on the liquid 127 In addition, noises generated during compression and deformation of the lower rubber body 120 would occur, through the liquid 127 absorbed, which contributes to improving noise, vibration and harshness (NVH).

[0066] Although the exemplary embodiments of the present invention have been described for illustrative purposes, it will be apparent to those skilled in the art that various modifications, additions and substitutions are possible without departing from the scope of the present invention as disclosed in the accompanying claims.

Claims

[1] A silencer (100) for a leaf spring (10) for a commercial vehicle, the silencer (100) comprising: an upper rubber body (110) in which a fitting hole (111) is defined into which a second leaf spring (12) can be pressed, wherein an upper surface of the upper rubber body (110) serves as a contact surface for contact with a first leaf spring (11), and a lower rubber body (120) in which a receiving space (121) is defined, wherein a first damper projection (122) is provided on a lower surface of the lower rubber body (120) and is arranged to come into contact with a third leaf spring (13). [2] The muffler (100) according to claim 1, further comprising a metal insert (113) housed within the upper rubber body (110), the metal insert (113) being configured to support the second leaf spring (12) press-fitted into the fitting hole (111) and reinforce the upper rubber body (110). [3] The muffler (100) according to claim 2, further comprising a plurality of coupling holes (126) provided in the metal insert (113), the plurality of coupling holes (126) being coupled to the upper rubber body (110). [4] The silencer (100) according to claim 2 or 3, further comprising a position fixing projection (115) provided at a central portion of the metal insert (113), wherein a locking projection (114) protrudes from an upper surface of the fitting hole (111) into which the second leaf spring (12) is press-fittable. [5] The silencer (100) according to claim 4, wherein the second leaf spring (12) further has a locking hole (117) and the locking projection (114) is lockingly insertable into the locking hole (117). [6] The muffler (100) according to any one of the preceding claims, wherein the lower surface of the lower rubber body (120) has an inclined surface (123) inclined downwardly toward the first damper projection (122). [7] The muffler (100) according to any one of the preceding claims, further comprising a second damper projection (124) provided on a lower surface of the damper space (121) of the lower rubber body (120), the second damper projection (124) having a convex shape extending upward at a position aligned with the first damper projection (122) in an up-down direction. [8] The muffler (100) according to any one of the preceding claims, further comprising a partition wall (126) having a passage (125) provided in the damper space (121) of the lower rubber body (120), the partition wall (126) dividing the damper space (121) into a left damper space (121-1) and a right damper space (121-2). [9] The muffler (100) according to claim 8, further comprising a liquid in the left and right muffler chambers (121-1, 121-2). [10] A vehicle comprising: a leaf spring device (10) comprising a first leaf spring (11), a second leaf spring (12) and a third leaf spring (13), and a silencer (100) attached to the leaf spring device (10), the silencer (100) comprising: an upper rubber body (110) having a fitting hole (111), wherein the second leaf spring (12) is pressed into the fitting hole (111), and wherein an upper surface of the upper rubber body (110) contacts the first leaf spring (11), and a lower rubber body (120) having a receiving space (121) and a first damper projection (122) arranged on a lower surface of the lower rubber body (120), wherein the first damper projection (122) is configured to contact the third leaf spring (13). [11] The vehicle according to claim 10, further comprising vehicle mounting bushings (18) arranged at both ends of the second leaf spring (12). [12] The vehicle according to claim 10 or 11, further comprising a metal insert (113) housed inside the upper rubber body (120), the metal insert (113) supporting the second leaf spring (12). [13] The vehicle according to claim 12, further comprising: a position fixing projection (115) at a central portion of the metal insert (113), a locking projection (114) projecting from an upper surface of the fitting hole (111), and a plurality of coupling holes (116) in the metal insert (113). [14] The vehicle according to claim 13, further comprising a locking hole (117) in the second leaf spring (12), wherein the locking projection (114) is inserted into the locking hole (117). [15] The vehicle according to any one of claims 10 to 14, wherein the muffler (100) is formed using vulcanization molds. [16] The vehicle according to any one of claims 10 to 15, further comprising: a hollow damper chamber (121) in the lower rubber body (120) and a second damper projection (124) provided on a lower surface of the hollow damper space (121) and aligned with the first damper projection (122) in an up-down direction. [17] The vehicle according to any one of claims 10 to 16, further comprising a damper chamber (121) in the lower rubber body (120), a partition wall (126) provided in the damper chamber, the partition wall (126) having a passage (125) and dividing the damper chamber (121) into a left damper chamber (121-1) and a right damper chamber (121-2), and a liquid (127) contained in the left and right damper chambers. [18] The vehicle according to any one of claims 10 to 17, further comprising an inclined surface (123) on a lower surface of the lower rubber body (120), the inclined surface being inclined downwardly toward the first damper projection (122). [19] A method for performing a multi-stage damping operation of a muffler (100) mounted on a leaf spring device (10) comprising a first leaf spring (11), a second leaf spring (12) and a third leaf spring (13) connected in a stack, the method comprising: during a shock behavior, performing a first damping operation comprising bringing a first damping projection (122) provided on a lower rubber body (120) of the muffler (100) into contact with an upper surface of the third leaf spring (13), and during the impact behavior, performing a second damping operation comprising compressing the lower rubber body (120), reducing the height of a damping space (121) provided in the lower rubber body (120), and bringing a second damping projection (124) provided on a lower surface of the lower rubber body (120) into contact with an upper surface of the damping space (121). [20] The method according to claim 19, further comprising: to move a central part of the leaf spring device (10) downwards during a rebound behavior in order to increase the distance between the second leaf spring (12) and the third leaf spring (13), during the rebound behavior, restoring the lower rubber body (120) to its original position, and during the rebound behavior, restoring a spring constant of the leaf spring device (10).

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