JP5291516B2 - Damper fixing jig and manufacturing method thereof - Google Patents

Abstract

The invention provides a damper fixing clamp apparatus which can improve the welding strength between a fixing plate and a cylindrical bolt and effectively prevent welding spatters from accumulating in a thread groove of the cylindrical bolt in the stud arc welding process and a manufacturing method thereof. The damper fixing clamp apparatus (1) includes a fixing plate (2) and a cylindrical bolt (3); a cone portion (34) is formed on a part of the root portion on the cylindrical bolt (3) on a side of a bolt head (33) of a main shaft (31); the bolt head (33) is formed with a protuberant portion (35); the damper fixing clamp apparatus also includes: a first welding portion (41) which is formed on an abutted position of the cone portion (34) and a bolt plug hole (21) along with the stud arc welding under the pressurization state when the main shaft (31) is inserted into the bolt plug hole (21) of the fixing plate (2); and a second welding portion (42) which is formed on the abutted position of the protuberant portion (35) and the fixing plate (2) through pressurization in a melting state of the first welding portion (41).

Description

  The present invention relates to a damper fixing jig that is used, for example, for attaching a damper that is interposed between an engine and a chassis of a vehicle body and absorbs vibrations from the engine, and a manufacturing method thereof.

  In order to prevent the vibration of an engine such as an automobile from being transmitted directly to the vehicle body, a structure in which a damper for supporting the engine and absorbing the vibration is interposed between the engine and the chassis of the vehicle body is adopted. There is a case.

  In order to attach such a damper between the engine and the chassis of the vehicle body, for example, as shown in FIG. 5, a damper fixing jig 1 in which a stud bolt 3 is arc stud welded to a fixing plate 2 is applied, and this damper is applied. The fixing jig 1 is fixed integrally on the top and bottom of the damper D using rubber, and the damper D is fixed to the engine and chassis (not shown) with nuts by the stud bolts 3 of the damper fixing jig 1.

  As shown in FIG. 6, the conventional damper fixing jig 1 forms a bolt insertion hole 21 at the center of the fixing plate 2, while the stud bolt 3 has a main shaft 31 having a thread groove 32 on one end side. A plurality of projections 35 are formed along the circumferential direction on the surface of the formed bolt head 33 on the main shaft forming side.

  When the stud bolt 3 is arc stud welded to the fixing plate 2, first, the main shaft 31 of the stud bolt 3 is inserted into the bolt insertion hole 21 of the fixing plate 2 as shown in FIG. The part 35 is brought into contact with the fixing plate 2. Next, as shown in FIG. 6B, an arc current is passed between the fixing plate 2 and the stud bolt 3 while applying pressure in this state, so that an arc is generated between the protrusion 35 and the fixing plate 2. Electric discharge is generated to weld between the two and 35 (for example, see Patent Document 1 below).

JP-A 63-238977

  By the way, in the conventional damper fixing jig 1, the main shaft 31 is formed to have the same outer diameter along the axial direction from the tip side to the base side of the bolt head 33. Therefore, when arc stud welding is performed, if the main shaft 31 of the stud bolt 3 is inserted into the bolt insertion hole 21 of the fixing plate 2 in advance, the projection 35 directly contacts the fixing plate 2 as shown in FIG. . Further, in order to smoothly insert the main shaft 31 of the stud bolt 3 into the bolt insertion hole 21, the outer diameter of the main shaft 31 is slightly smaller than the inner diameter of the bolt insertion hole 21.

  Therefore, when arc stud welding is performed while pressing the stud bolt 3 toward the fixed plate 2 at a predetermined pressure in the state shown in FIG. 6A, as shown in FIG. 42 is formed only at the contact point between the projection 35 and the fixed plate 2. For this reason, the welding strength between the fixing plate 2 and the stud bolt 3 is still insufficient.

  Moreover, as shown in FIG. 7, the spatter 5 melted during arc stud welding passes between the bolt insertion hole 21 and the bolt main shaft 21 and scatters to the main shaft 31 protruding above the fixing plate 2. As a result, the sputter S is clogged in the thread groove 32 formed in the main shaft 31, and as a result, there may be a problem that the nut cannot be tightened smoothly.

  In the prior art described in Patent Document 1, a ring-shaped insulating member is provided at the base portion of the main shaft 31 and the bolt head 33 so that the spatter 5 does not scatter to the thread groove 32 portion of the main shaft 31 during arc stud welding. Although it is fitted, it is not a good idea to use such an insulating member separately because of the extra labor and cost.

  The present invention has been made in order to solve the above-described problems, and a stud bolt can be more firmly welded to a fixed plate than in the past, and during arc stud welding, spatter is scattered to the main shaft and screwed. It is an object of the present invention to provide a damper fixing jig and a method for manufacturing the same that can reliably prevent the occurrence of problems such as clogging of sputters in grooves.

  In order to achieve the above object, the present invention adopts the following configuration.

  That is, the damper fixing jig according to the first aspect of the present invention includes a fixing plate that is integrally fixed to the damper, and a stud bolt that is arc stud welded to the fixing plate, and the fixing plate includes the stud bolt. A bolt insertion hole through which the main shaft of the main shaft is inserted is formed. On the stud bolt, a plurality of protrusions are formed along the circumferential direction on the main shaft forming surface of the bolt head formed on one end side of the main shaft. In addition, a taper portion whose outer diameter gradually becomes larger than the inner diameter of the bolt insertion hole as it reaches the bolt head is formed at the base portion on the bolt head side of the main shaft, and the bolt insertion hole Along with the arc stud welding in a pressurized state through the main shaft, the first welded portion formed at the contact portion between the tapered portion and the inner peripheral portion of the bolt insertion hole, and the first Melting The pressure in solution parts are characterized by having, a second weld portion formed in contact portion between the projection and the fixed plate.

    According to a third aspect of the present invention, there is provided a damper fixing jig manufacturing method wherein when the damper fixing jig according to the first aspect is manufactured, the stud bolt main shaft is inserted into the bolt insertion hole of the fixing plate. Then, the step of bringing the taper portion into contact with the inner peripheral portion of the bolt insertion hole, and in this state, while pressing the stud bolt toward the fixing plate with a predetermined pressure, between the fixing plate and the stud bolt. Arc stud welding is performed by passing an arc current through the step, forming a first welded portion at a contact point between the tapered portion and the inner peripheral portion of the bolt insertion hole, and then the first welded portion is And a step of bringing the protruding portion and the fixing plate into contact with each other by pressurization when in a molten state, and forming a second welded portion at the contact portion.

  According to the present invention, the damper fixing jig has two welding locations between the fixing plate and the stud bolt, the first welded portion and the second welded portion. Stud bolts can be more strongly welded to the plate.

  In addition, in arc stud welding, the contact portion between the taper portion and the inner peripheral portion of the bolt insertion hole of the fixing plate precedes the formation of the second welding portion at the contact portion between the protrusion and the fixing plate. Is melted to form the first welded portion, thereby closing the gap between the main shaft and the bolt insertion hole. As a result, the spatter generated when the second welded portion is formed at the contact portion between the protruding portion and the fixing plate is scattered to the main shaft protruding above the fixing plate through the bolt insertion hole and screw grooves. It is possible to reliably prevent problems such as spatter clogging.

  In the above, if the depressed portion is formed at the contact portion with the projection portion of the fixing plate, the effect of the present invention can be further enhanced.

It is a perspective view which shows the fixing plate and stud bolt which comprise the damper fixing jig in embodiment of this invention. In the same damper fixing jig, a vertical sectional side view for explaining a case where a stud bolt is fixed to a fixing plate. FIG. 4A is a state where the stud bolt is inserted into the fixing plate, and FIG. The state after arc stud welding of a stud bolt is shown, respectively. It is a perspective view of the damper fixing jig of the present invention. It is a vertical side view which shows another embodiment of this invention, The figure (a) is the state which inserted the stud bolt into the fixing plate, The figure (b) is the state after arc stud welding the stud bolt to the fixing plate. Respectively. It is a side view of the state which attached the damper fixing jig to the damper. In a conventional damper fixing jig, a vertical sectional side view for explaining a case where a stud bolt is fixed to a fixing plate. FIG. 5 (a) shows a state in which the stud bolt is inserted into the fixing plate, and FIG. Fig. 6 shows the state after arc stud welding of the stud bolt. It is a perspective view which shows the fixing plate and stud bolt which comprise the conventional damper fixing jig.

  FIG. 1 is a perspective view showing a fixing plate and a stud bolt constituting a damper fixing jig in Embodiment 1 of the present invention, and FIG. 2 is a case where a stud bolt is fixed to the fixing plate in the damper fixing jig. FIG. 3 is a longitudinal side view for explanation, and FIG. 3 is a perspective view.

  The damper fixing jig 1 in this embodiment includes a substantially disc-shaped fixing plate 2 that is integrally fixed to the damper D, and a stud bolt 3 that is stud-welded to the fixing plate 2.

  A bolt insertion hole 21 through which the main shaft 31 of the stud bolt 3 is inserted is formed in the fixing plate 2. On the other hand, in the stud bolt 3, a screw groove 32 is formed on the main shaft 31, and a bolt head 33 is integrally provided on one end side of the main shaft 31. In this case, the outer diameter of the portion where the thread groove 32 of the main shaft 31 is formed is slightly smaller than the inner diameter of the bolt insertion hole 21, but the base portion of the main shaft 31 on the bolt head 33 side gradually increases as it reaches the bolt head 33. A tapered portion 34 having a diameter larger than the inner diameter of the bolt insertion hole 21 is formed. A plurality (four in this example) of protrusions 35 are formed on the surface of the bolt head 33 on the main shaft forming side along the circumferential direction. In this case, it is sufficient that the number of the protrusions 35 is two or more, but here, the case of four is shown. Moreover, it is preferable that the protrusions 35 are formed at equal intervals along the circumferential direction of the bolt head 33 in order to keep the welding strength uniform during arc stud welding.

  Further, in the damper fixing jig 1 of this embodiment, the taper portion 34 is obtained by inserting the main shaft 31 into the bolt insertion hole 21 of the fixing plate 2 and performing arc stud welding in the pressurized state as follows. And a first welded portion 41 formed at the contact portion between the bolt insertion hole 21 and the inner peripheral portion of the bolt insertion hole 21, and a second welded portion 42 formed at the contact portion between the projection 35 and the fixing plate 2. have.

  To manufacture the damper fixing jig 1 having the above-described configuration, as shown in FIG. 2A, the main shaft 31 of the stud bolt 3 is inserted into the bolt insertion hole 21 of the fixing plate 2 and the taper portion 34 is inserted into the bolt insertion hole. It is made to contact | abut to the inner peripheral part of 21. FIG. In this case, since the outer diameter of the bolt head side proximal end portion of the taper portion 34 is larger than the inner diameter of the bolt insertion hole 21, the protruding portion 35 does not contact the fixing plate 2, and there is a slight gap between the two and 35. There is a gap Lo. In this state, the stud bolt 3 is pressed toward the fixing plate 2 with a predetermined pressure (see the arrow in FIG. 2), while the outside of the fixing plate 2 (upper side in FIG. 2) and the bolt head 33 of the stud bolt 3. Arc stud welding is performed by flowing an arc current between the outside (the lower side in FIG. 2).

  As a result, arc discharge is generated at the contact portion between the tapered portion 34 and the inner peripheral portion of the bolt insertion hole 21 of the fixing plate 2, thereby forming the first welded portion 41. At that time, first, the contact portion between the tapered portion 34 and the bolt insertion hole 21 is melted, and the gap between the main shaft 31 and the bolt insertion hole 21 is immediately closed by the applied pressure.

  Next, even when the first welded portion 41 is in a melted state, the pressurizing state continues, so that each projection 35 and the fixing plate 2 come into contact with each other, and an arc is formed at the contacted portion. Discharge occurs and the second weld 42 is formed.

  As described above, the damper fixing jig 1 according to this embodiment has the first and second welded portions 41 and 42 formed between the fixing plate 2 and the stud bolt 3, so that the welded portion is more than conventional. Therefore, the stud bolt 3 is more strongly welded to the fixed plate 2.

  For example, a stud bolt 3 having an outer diameter of the main shaft 31 is 12 mm, an arc current of 33 kA is passed under a pressure of 4 kg, and arc stud welding is performed. When the force until the bolt 3 was separated and broken was measured, the conventional product shown in FIG. 6 could only obtain a breaking strength of about 2 tons at the maximum, but the product of the present invention had a maximum of about 5 tons. It was confirmed that fracture strength was obtained and sufficient welding strength could be secured.

  Moreover, when the same structure was proposed for the stud bolt 3 having a diameter of 16 mm, the separation fracture was 6 tons or more.

  Moreover, in arc stud welding, the contact portion between the taper portion 34 and the bolt insertion hole 21 precedes the formation of the second weld portion 42 at the contact portion between the projection 35 and the fixing plate 2. Since the first welded portion 41 is formed by melting, the gap between the main shaft 31 and the bolt insertion hole 21 is closed by the first welded portion 41. Thereby, spatter generated when the second welded portion 42 is formed passes through the bolt insertion hole 21 and scatters to the main shaft 31 protruding upward from the fixing plate 2, so that the spatter is clogged in the screw groove 32. Can be reliably prevented from occurring.

  FIG. 4 shows another embodiment of the present invention.

  A depressed portion 36 that coincides with the projection 35 is formed at a position corresponding to the projection 35 of the fixing plate 2. As a result, the protrusions 35 are fitted into the depressions 36 and melted during welding, and a higher welding strength (for example, a breaking strength of 6 tons with a 12 mm diameter stud bolt) can be obtained.

  According to the present invention, a stud bolt can be welded to a fixed plate more firmly than in the past, and when arc stud welding, spatter is scattered to the main shaft and the occurrence of defects such as spatter clogging in the thread groove is ensured. It can be prevented, and is useful as a damper fixing jig and a manufacturing method thereof, and can be used as various fixing jigs.

DESCRIPTION OF SYMBOLS 1 Damper fixing jig 2 Fixing plate 21 Bolt insertion hole 3 Stud bolt 31 Main shaft 32 Screw groove 33 Bolt head 34 Taper part 35 Projection part 36 Depression part 41 First welding part 42 Second welding part

Claims (4)

A fixed plate that is integrally fixed to the damper, and a stud bolt that is arc stud welded to the fixed plate;
While the fixing plate is formed with a bolt insertion hole through which the main shaft of the stud bolt is inserted,
In the stud bolt, a plurality of protrusions are formed along the circumferential direction on the surface of the main shaft forming side of the bolt head formed on one end side of the main shaft, and at the base portion on the bolt head side of the main shaft, A tapered portion is formed in which the outer diameter gradually becomes larger than the inner diameter of the bolt insertion hole as it reaches the bolt head,
And, as the main shaft is inserted into the bolt insertion hole of the fixing plate and arc stud welding is performed in a pressurized state, the taper portion and the inner peripheral portion of the bolt insertion hole are formed at contact points. It has a 1st welding part and the 2nd welding part formed in the contact part of the above-mentioned projection part and the above-mentioned fixed plate by pressurization of the melting state of this 1st welding part, It is characterized by the above-mentioned. Damper fixing jig. The damper fixing jig according to claim 1, wherein a depressed portion into which the protruding portion is fitted is provided at a position on the fixing plate corresponding to the protruding portion. A method of manufacturing the damper fixing jig according to claim 1,
Inserting the main shaft of the stud bolt into the bolt insertion hole of the fixing plate and bringing the outer periphery of the tapered portion into contact with the inner periphery of the bolt insertion hole;
In this state, while pressing the stud bolt toward the fixed plate at a predetermined pressure, an arc current is passed between the fixed plate and the stud bolt to perform arc stud welding, and the taper portion and the bolt insertion hole Forming a first weld at a contact point with the inner periphery;
Then, the step of bringing the protruding portion and the fixing plate into contact with each other by pressurization when the first welding portion is in a molten state, and forming a second welding portion at the contact portion;
The manufacturing method of the damper fixing jig characterized by including. The method for manufacturing a damper fixing jig according to claim 3, wherein a depressed portion into which the protruding portion is fitted is provided at a position on the fixing plate corresponding to the protruding portion.