JPS5925357B2 - Manufacturing method of blade holder spring - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a blade support spring, in which a large number of blade support springs are continuously formed by punching and bending a band-shaped metal plate.

In the case of a blade retaining spring that has a structure in which the blade is inserted into a pair of opposing blade retainers with one opening open, the blade retaining spring has a configuration in which the blade is held with one opening opening. If the narrowest distance between the pieces 1 and 1 is different in the direction perpendicular to the inserting direction of the blade, the holding force against the blade will be greater than when the distance is the same as shown in Fig. 2. Managing dimensional accuracy becomes easier.

In order to form the plug blade holding pieces 1, 1 as shown in FIG. It would be sufficient to make the curve B oblique by an angle α and then bend the bases of both protruding pieces 2, 2 so that both protruding pieces 2, 2 face each other, but in this case, the following problem occurs. arise. In other words, when forming the membranes based on Fig. 4, when forming the blade retaining springs continuously by punching and bending, first, as shown on the left side of the figure, separation grooves are formed at positions corresponding to the gaps between the respective blade retaining springs. Form the T by punching,
Then, a groove 3 separating the pair of protrusions 2, 2 is formed. After this, each protruding piece 2 is bent to form the step 6 as described above, and then the base of the protruding piece 2 is bent to form a pair of protruding pieces 2.
, 2 to form the opposing blade retaining blades 1, 1, but due to the separation groove T, a considerable amount of material is lost. When machining the protruding piece 2 into the step 6, the gap between the pair of protruding pieces 2 and 2 becomes wider toward the tip.As a result, the other line of the tip of the protruding piece 2 is When close to the separation groove T, a certain width is required to prevent overlap.
This results in material loss. If the separation groove T is formed by shear 9 fern instead of punching,
During the bending process for attaching the step 6, the projecting pieces 2 cross each other, making it impossible to perform the bending process at the next station. The present invention has been made in view of the above points, and its purpose is to provide a blade that can continuously manufacture blade receiving springs with a blade retaining piece having a large holding force at a high yield rate. The present invention provides a method for manufacturing a receiving spring. The present invention will be described in detail below with reference to the drawings. Fig. 5 is a plan view sequentially showing the manufacturing process of an embodiment of the present invention, in which a strip metal plate A having a pilot hole 8 is shown on the right side of the figure. Processing is performed sequentially by step feeding.

First, as a first step, relief grooves 4 and grooves 3 are formed on one side edge of the band-shaped metal plate A by punching. Similar to the separation groove 7 of the conventional example, the relief groove 4 is used to ultimately separate each blade receiving spring from this part, and the groove 3 is used to partition the pair of protrusions 2, 2. Therefore, the escape groove 4 is shorter than the groove 3. After this punching process, a shearing process is performed,
A shearing portion 5 continuous to the relief groove 4 is formed. This shearing process may be performed simultaneously with the first punching process. After forming the grooves 3, relief grooves 4, and shearing portions 5 in this manner, the protruding pieces 2 separated by these are subjected to a bending process. This bending process is performed by forming a pair of protrusions 2, 2 with a groove 3 between them, and first bends the tip, and then bends the protrusion 6 to form a step 6 in the middle. In this latter bending process, as shown in FIG. Make it wider towards the tip. At this time, although the other edge of the tip of the protruding piece 2 approaches the adjacent protruding piece 2, it does not overlap due to the existence of the relief groove 4. After this, a pair of protrusions 2, 2
A pair of opposing blade holding pieces 1, 1 are formed by bending the base of the blade.
It forms. In addition, the maximum stress point of the blade spring is at the first
Since it is considered to be part E in the figure and part F in Fig. 5, the depth of the relief groove 4 is set at the innermost end of the relief groove 4 at a position shifted from this part E-F or at a position including the folding line B. It is considered best to locate the As described above, in the present invention, not only can the retaining force of the plug blade be kept high, but also the clearance groove prevents the projecting pieces from crossing each other during the bending process for this purpose. The two stress points have the same cross-sectional moment of inertia, and can be constructed without deteriorating the spring characteristics such as stress holding force compared to the conventional product.1Moreover, the part continuous to the relief groove is a shearing part, so the final cut b Not only can they be separated, but there is also less material loss and costs can be reduced.

[Brief explanation of drawings]

Figure 1 is a front view of the blade retainer spring, Figure 2 is a front view of another blade retainer spring, Figure 3 is a developed plan view of the blade retainer spring in Figure 1, and Figure 4 is a diagram of the conventional manufacturing method. 5th plan view showing the manufacturing process of
The figure is a plan view of the manufacturing process according to the present invention, and 1 is a blade holding piece, 2 is a projection piece, 3 is a groove, 4 is a clearance groove, 5 is a shearing part, and 6 is a step.

Claims (1)

[Claims] 1 A band-shaped metal plate is punched to form a large number of protrusions in pairs, and then the base of each protrusion is bent so that the pair of protrusions face each other to form a pair of plug blades. In a method for manufacturing a blade retaining spring forming a holding piece, punching is performed on one side of a band-shaped metal plate to form grooves and relief grooves alternately, and a shirring process is applied to continue the relief grooves. A large number of protrusions separated by these grooves, relief grooves, and shirred parts are formed, and then each protrusion is bent in a direction perpendicular to the surface of the band-shaped metal plate to form the tip of the protrusion. At the same time as forming a step, the gap between a pair of adjacent protrusions is given to the protrusions via a groove so that the gap becomes wider toward the tips, and then the bases of the pair of protrusions are bent so that they face each other and the tips A method for manufacturing a blade holder spring, comprising forming blade retaining pieces having different intervals in a direction perpendicular to the insertion direction of the blade.