JPS58181409A - Dust sealing piece of drum brake - Google Patents

Abstract

PURPOSE:To reduce cost, by formig a strip-shaped branch into a L-shaped cross section having plate-surfaces perpendicularly intersecting each other, and rolling it, by making one side of the plate-surface larger in draft than that of the other plate-surface, with the aid of a roll. CONSTITUTION:Both end parts 4 of a strip-shaped blank front material 3, having approximately the same length as that of the outer circumference of a back plate of a drum brake and the prescribed width, are cut to bend it into an intermediate blank material 3A having a prescribed cross-sectional shape with the aid of a roll or a bender. Next the material 3A is rolled by holding it between a pair of upper and lower rolls 12, 13. At this time, the straight material 3A is bent into an annular shape by rolling a radially larger part of a dust sealing piece, i.e. a plate-surface 32, by a larger rolling draft. Thus, an annular dust sealing piece, having a cylindrical plate-surface 32c and a flat plate-surface 32b perpendicularly intersecting to the axial line of the cylindrical surface 32C, is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention prevents dust from entering the inside of the brake drum from the opening end of the brake drum in a drum brake and the abutment part between the opening end of the brake drum and the outer peripheral edge of the root. It is related to the dust shield that prevents.

Generally, as shown in FIG. 1, a drum brake has a brake drum 31 that rotates together with the wheels.
Braking force is obtained by engaging the pair of brake shoes in one stroke, and the back plate 2 that covers the open end of the play 1 drum 31 is provided with a hole 34 in the center through which the fist shaft passes. The part surrounding the 'a hole 34 is attached to the non-rotating part of the thread by bolts. Then, a hydraulic cylinder @1 and an annular member are fixed to the inner surface of the back plate 2, and a brake shoe 1 is engaged 32Nj between the two.

In this way, the back plate 2 not only guides and supports the brake shoes, but also prevents them from receiving the illumination torque of the brake shoes.
Furthermore, the m1 length plays the role of closing the brake drum.

The conventional Dasu I-shield 32, which is used to prevent dust from entering the inside of the brake drum, has a thinner annular plate 2 on the back plate 2, which is thick enough to withstand braking torque. A rounded portion 32c is formed by bending a flat plate into a single cross-sectional shape, which is then expanded outwardly from the back plate 2 to a size of about 6, and is joined by welding.

Since such a conventional dust shield 32 requires punching out an annular plate from a flat plate, the effective utilization rate of the material is extremely low, which is disadvantageous in terms of cost.

On the other hand, there is a method of continuously constructing a dust shield from coil material by roll forming, but this method can only use coil material as the material and cannot use strip material. Moreover, the rolling equipment and the equipment attached thereto become enormous, which is disadvantageous in terms of cost for producing a wide variety of single products.

There is also a spinning method,
This is not good in production efficiency because the processing time per piece is long and welding is required to join the strips into a cylindrical shape.

In view of these problems, an object of the present invention is to obtain an annular body having a desired cross-sectional shape from a long plate, that is, a rectangular plate using simple equipment, thereby saving material costs and reducing equipment costs. The objective is to provide a drum brake dust shield that makes it possible to reduce dust.

For this reason, in the present invention, a rectangular plate is first formed into a rectangular cross-section with plate surfaces perpendicular to each other, and then one of the plate surfaces is rolled with a roll at a rolling rate higher than the rolling rate. In this way, the dust shield is cut in a circular manner to obtain the required dust shield.

In other words, the structure of the present invention is to diagonally cut a part of both edges of a %all-shaped material having the same length and predetermined width as the outer corner of the back plate of the drum brake, and then cut the ends of the material from AM material to each other. The cross section with one plate surface that intersects is formed into a medium-sized lumber with a cross section, and the lA material is rolled in an O- The annular body having the above-mentioned lIi mountain shape is obtained by rolling.

The present invention will be described based on an embodiment. As shown in FIG. 2, the present invention is characterized in that an annular dust shield 32 having a required 1lIITl shape is formed from a %1III type steel plate, that is, a cable material 3. First, as shown in FIG. 3, one end 4 of the cable material 3 is cut diagonally, and
As shown in the figure, a medium-sized lumber 3A is obtained by bending it into a desired cross-sectional shape using a roll or a solder.

Next, as shown in Fig. 15, the medium-sized lumber 3A is sandwiched between a pair of upper and lower rolls 12, 13 and rolled. In this case, by increasing the rolling ratio of the radially outer portion of the dust shield, that is, the plate surface 32Q, the straight 1 ml material 3A is bent into an annular shape. - the drive axes 5.15 of the rolls 12.13 are arranged parallel to each other; The roll 12 has a flange surface 6 that fits IfI to one end edge of the medium-sized lumber 3A, a circumferential surface 7 parallel to the axis 5 corresponding to the plate surface 32c, and a conical surface 8 corresponding to the bent portion 32d.
It has a flange surface 9 corresponding to the plate surface 32b. Similarly, the 0-rule 13 also has seven flange 16 corresponding to the plate surface 32b of the middle-III material 3A, a conical surface 17 adjacent thereto, and a circumferential surface 18 parallel to the axis 15.

When forming an annular body from medium-sized lumber 3A using a pair of rolls 12.13, an external force is applied to the shafts 5 and 15 in the direction of approaching each other, and the plate surface 32c1g is formed by the circumferential surface 6.18.
Perform rolling processing.

The rolling rate applied to the plate surface 32c with the circumference of 116.18 is
The plate surface 32b#P: is made larger than the applied rolling rate by the two flange surfaces 9 and 16, so that the pallet shown in FIG.
Gunanaka 111143A is bent into a ring shape. By cutting the hooked end 4 of the medium-sized lumber 3A diagonally in advance, the elongation due to the difference in rolling ratio between the plate surface 32b and II+32c is absorbed, and as shown in FIG. Both ends 4 are almost aligned.

By the way, conventionally, when trying to form an annular body having a desired cross-sectional shape from a rectangular plate using rolls, the inner F1
4II, that is, wrinkles were formed on the plate surface perpendicular to the central axis, and a satisfactory product could not be obtained.

According to the present invention, after forming the required 1Iilfi-shaped medium-sized lumber that warms the flat surfaces perpendicular to each other as described above, one plate surface of the medium-sized lumber is coated with the other side. Since the rolling rate is higher than that of the plate surface and the pressure is applied by an O-roll, an annular dust shield 32 having a cylindrical Matsuyama 32c and a flat plate 1f 132b orthogonal to this central axis is formed. Can be molded. Since rectangular boards are used as the lumber, it is also suitable for small-scale production.

In addition, compared to continuous rolling using coiled material, the machinery and equipment are simpler, the installation space for the equipment is less, and production can be done with a small investment in equipment, so it can be manufactured in small quantities and in a wide variety of products (mainly circular bodies of one diameter). You can get the excellent effect of being able to provide products at low prices.

In the embodiment shown in FIG. W47, a roll 23 with a rising shape is used, and the shaft 25 of the roll 23 is tilted with respect to the shaft 5 of the roll 12 to be lifted. The roll 23 is 1] - the conical surface 8 of the roll 12
A groove-shaped one is adopted, which has a circumferential surface 27 corresponding to the circumferential surface 27, a conical surface 26 facing the seven flange 9 on both sides of the circumferential surface 27, and a conical surface 28 opposing the circumferential surface 7.

In this embodiment, by changing the inclination 8 of the roll 230 axis 25, the ratio of the rolling ratio of the plate surface 32C to the plate surface 32b can be changed.

In addition, in the above-mentioned embodiment, the circle Ill direction 32d is formed on the plate surfaces 32b and 32c which are orthogonal to each other.
- Although we have explained the case of a shield, as shown in Fig. 8, the plate surface 32b and plate surface 32C are 4M,
Even in the case of a comb-shaped dust shield, it can be formed from a rectangular shape by changing the shape of the roll.

[Brief explanation of the drawing]

Figure 1 is a side sectional view showing the installed state of the dust shield and the relationship between the pocket brake drum and the plate, Figures 2 and 3
Figure 144 is a perspective view of the electric material used for the TAS shield according to the present invention, Figure 144 is a perspective view showing the intermediate forming state of the four-piece material,
Fig. 5 is a side view of an apparatus for forming an annular dust shield from intermediate lumber, Fig. 6 is a perspective view of a CIR-shaped dust shield according to the present invention, and Fig. 17 is a front view showing another forming position. FIG. 1188 is a perspective view showing another embodiment of the dust shield. 2: Marozawa 3: Jll material 4: End 12.13.23
: Roll 31 Nil-Kitram 32: Dust shield 32b, 32c : Board patent issuer Cheer brake■
Higashi Co., Ltd. Agent Patent Attorney Toshito Yamamoto Issun @2! l fist 5 w 311 7 w

Claims (1)

[Claims] A part of both ends of a rectangular material having approximately the same length and a predetermined width as the outer circumference of the back plate of a drum brake is cut diagonally, and the cross section of the material with plate surfaces perpendicular to each other is the middle of the shape of a rectangular shape. A drum characterized in that a material is formed and the intermediate material is rolled so that one plate surface has a higher rolling rate than the other plate surface to obtain an annular body having the above-mentioned cross-sectional shape. Brake dust shield.