JPS6237639Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an endless sand belt with a novel structure used for grinding wood substrates having uneven surfaces for furniture and other woodworking members.

In recent years, woodworking machinery has made remarkable progress, and even the final smoothing of material surfaces with complex curves can now be done using grinding machines with various functions, further improving the efficiency of woodworking work. What has been happening is well known. Sanding by this grinding machine (belt sander) can be understood from Fig. 2, which shows an embodiment of this invention. So-called platen grinding, in which the belt is wound and run at high speed, and the back surface of the belt is pressed against the curved surface c of the workpiece b, which has been machined into a surface shape, with a pad (platen) e having a female curved surface d, while grinding. Many methods are used.

By the way, the degree of smoothing achieved by the conventional platen grinding method tends to be such that the more complex the curved surface of the material to be ground, the rougher and more uneven the surface roughness. The cause should have been the structure of the grinding tool, that is, the sand belt, rather than the grinding machine itself. The conventional sand belt
As shown in the figure, it is made of medium-hard single-sided solid abrasive paper cloth with hard abrasive grains adhered to the surface, and has sufficient flexibility to follow complex curved surfaces. Therefore, it is difficult for the sand belt f running at high speed to locally and instantaneously cause a combined bending action of compression and tension by the pad g (or e), and it is difficult to conform to the curved shape of the pad. As a result, many wrinkles h, h... were generated on the belt surface, and the degree of smoothness of the surface of the material was extremely poor, making it difficult to achieve the purpose of the grinding process. In this way, in the conventional grinding and smoothing work of wood, although the ability of the grinding process itself has improved with the advancement of grinding machines, the development and improvement of the essential grinding tool, the sand belt, has lagged behind, making it difficult to smooth the surface of the material. In addition, the smoothing ability, which should provide a uniform finish, was unable to keep up with this.

This invention has been researched and improved in order to cope with such existing circumstances, and the details of its configuration will be explained below with reference to the accompanying drawings showing embodiments of this invention.

As can be understood from the overall perspective view of a typical embodiment of this invention shown in FIG. Cut portions 6, 6, . . . are formed intermittently at appropriate intervals 5 at intermediate width positions 4 excluding the portions.
The cut portion 6 is provided to impart sufficient flexibility to the sand belt 1 so that it can easily conform to the shape of the pad, and must penetrate both the front and back sides of the sand belt 1. The direction of the cut portion 6 is determined according to the embodiment shown in the drawings in consideration of ease of conformity to the pad of the sand belt 1, grindability (free machinability/finishability) of the material surface, wear resistance of the abrasive grains, etc. It is most convenient to form the sand belt in the diagonal width direction as shown in the example above, and the angle depends on various factors such as the rotation speed and direction of the sand belt 1, the belt width, the material and curved shape of the material to be ground, etc. The most suitable one must be selected after consideration. Also,
The interval 5 between the cutting parts 6 must be selected appropriately depending on the curved surface shape of the material to be ground and its complexity, and the length of the cutting parts 6 should be determined depending on the curved surface of the material to be ground or the belt width 3. It is preferable that it is formed appropriately depending on the size of the area. Although not shown in the drawings, these cut parts 6, 6... are not only arranged diagonally regularly, but also arranged in a staggered manner, or cut parts 6, 6...
Of course, it is possible to change the shape of each cut and to make other various changes.

As shown in Figs. 2 and 3, a typical example of the use of the endless sand belt of this invention is as shown in Figs. There are cases where the curved surface c is ground and smoothed (see FIG. 2), and where the inner curved surface j of the frame i is ground and smoothed using a rotary pad g (see FIG. 3). Here, to explain the relationship between the endless sand belt and the pads g and e, the sand belt 1 is pushed out toward the materials to be ground i and b by the pads g and e and pulled in the belt direction. The torn parts 6, 6, . . . of the sand belt 1 in the vicinity open the torn openings 6a, and the belt surfaces between the respective intervals 5 become in a state where they can move independently. Therefore,
The sand belt 1 absorbs all the wrinkles that would normally occur due to the combined external force of compression and tension received from the pad through the slits 6a of the slit portion 6, thereby affecting both edges in the width direction of the same belt. It becomes possible to perform a free bending action without being bent. As a result, the peripheral surface 2 of the sand belt 1 conforms to the curved shape of the pad and realizes a grinding process in which it runs smoothly at high speed without wrinkles.

As mentioned above, the endless sand belt of this invention has a cut portion 6 formed over the entire circumference of the belt,
6. Due to this, the belt has sufficient flexibility, can bend freely, and conforms to the complex curved surface shape of the pad, so it can smoothly and uniformly cover the complex curved surface of the material to be ground. Moreover, it can be precisely ground and smoothed. Moreover, since manufacturing of this endless sand belt can be achieved simply by applying tear-forming processing to a conventional sand belt, there is a risk that it will be economically more expensive than conventional products. Moreover, in terms of durability, the presence of both sides in the width direction makes it comparable to conventional products.

In this way, the endless sand belt of this invention provides a sand belt suitable for the evolving grinding machines, and can be said to make an extremely large contribution to improving the quality of wood grinding and smoothing work, and ultimately to processing efficiency.

[Brief explanation of the drawing]

Figure 1 is an overall perspective view showing a typical embodiment of the endless sand belt according to this invention;
The figure is an explanatory diagram showing the state of use, and Figure 3 is
FIG. 4 is an enlarged perspective view of the main part showing another state of use, and FIG.
FIG. 1... Sand belt, 2... Belt entire circumference, 3
... Belt width, 4 ... Middle width position of belt width, 5
... Distance between the cut parts 6, 6, 6... Cut part.

Claims (1)

[Scope of utility model registration request] An endless sand belt comprising continuous cut portions formed intermittently at regular intervals over the entire circumference of the belt at an intermediate width position excluding both ends in the belt width direction.