JPS6010387B2 - Sub chassis for video tape recorder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sub-chassis for a video tape recorder (hereinafter referred to as VTR), in particular, a sub-chassis in which a cylinder, an audio head, and mechanical members for mounting and running a magnetic tape thereon are mounted, and a central A subchassis for a VTR (hereinafter simply referred to as a subchassis) having a hole through which a bearing fixing part of a position cylinder passes through, and strip-like holes located on both sides of this hole to guide a guide base of a mechanism member. (There are also some cases.)

Conventional VTRs use aluminum die-cast products or pressed steel plate products as the sub-chassis, but in both cases, metal protrusions for attaching various parts are attached by caulking, screwing, etc. The disadvantage is that the manufacturing process is long.

In addition, aluminum die-cast products can be made into complex shapes to a certain extent, but because they require precision finishing, the number of production steps increases, and ``shapes can only be made complex to the extent that finishing machining is possible.'' On the other hand, in the case of pressed steel sheets, it is not possible to process very complex shapes, and the steel sheet has the disadvantage of warping or twisting during pressing. Since it uses metal, it is heavy and there is a limit to how much weight it can be reduced.The present invention eliminates these problems and provides a lightweight sub-chassis for VTRs that is less deformed over time and has high strength. It is equipped with a cylinder, an audio head, a magnetic tape device, and mechanical members for running the magnetic tape, and a hole located in the center through which the bearing fixing part of the cylinder passes, and this hole. In a sub-chassis for a VTR, the sub-chassis is made of a plastic molded body and has strip-shaped holes located on both sides of the sub-chassis for guiding a guide base of a mechanism section, and the sub-chassis is made of a plastic molded body, and the strip-shaped holes are formed on either one or both of the upper and lower sides of the sub-chassis. Reinforcement ribs are installed on the outside of the running area of the guide base along which the guide base runs and around the outside of the sub-chassis, and these reinforcing ribs are mutually continuous in one plane and are installed on the top and bottom of the sub-chassis, respectively. A first feature is that the reinforced rib surrounds the outside of the travel area of the guide vane and the outer periphery of the subchassis with an overlapping portion when projected,
In addition to the reinforcing ribs that are installed outside the running area of the guide base where the guide base runs along the band-shaped holes and around the outside of the subchassis, reinforcing ribs are also installed around the holes located in the center. The second feature is that

The present invention makes it possible to prevent deformation over time and cleave deformation, which are problems when plastic is used for a VTR sub-chassis, by using a lip-reinforcing structure, thereby making it possible to use plastic for a VTR sub-chassis.

This rib reinforcement structure is a structure in which reinforcing ribs are provided only on the upper and lower surfaces of the chassis, or on both the upper and lower surfaces, and also in a part of the reinforcing ribs provided to surround a predetermined area. It is used in various ways, such as a structure that does not have reinforcing ribs and can be engaged with other parts. Examples will be described below.

FIG. 1 is a plan view showing the basic structure of a VTR subchassis, and FIG. 2 is a plan view of an embodiment of the present invention.

In these figures, 1 is a hole through which the bearing fixing part of the shilling provided in the center is penetrated, and 2 is a hole,
A band-shaped hole is provided on both sides of the hole 1 and guides a guide base 3, which is a mechanical member for running the magnetic tape. Reference numeral 4 denotes a guide that runs around the band-shaped hole 2 and runs along the band-shaped hole 2. A running area of the base 3, 5 is a reinforcing rib installed outside the running area 4, and 6 is a reinforcing lip installed around the outer periphery of the sub-chassis. Both of the reinforcing ribs 5 and 6 are continuous, and the reinforcing ribs 5 and 6 are continuous with either the upper or lower surface of the sub-chassis as a whole. This VT
The subchassis for R is provided with a reinforcing lip in a shape that surrounds the band-shaped hole 2, and the reinforcing ribs 5 and 6 are continuous with each other and are continuous with either the upper or lower surface of the subchassis as a whole. Therefore, it is possible to eliminate deformations over time such as warping and twisting (in this figure, the normal state is shown by dotted lines) as schematically shown in Figure 3, and it is possible to increase the strength. Ta.

FIG. 4 is a plan view of another embodiment, in which the same parts in FIG. 1 and FIG. These reinforcing ribs 7 are connected to the reinforcing ribs 5 around the band-shaped holes 2 and the reinforcing ribs 6 around the outside of the sub-chassis.

This sub-chassis for VTR not only has band-shaped holes 2, but also
Reinforcing ribs 7 are also provided around the hole 1 located in the center, and these reinforcing ribs 7 are connected to the reinforcing lips 5 and 6, so deformation over time is further reduced and the strength is high. Become.

FIGS. 5a and 5b are top and bottom views of still another embodiment, in which the same parts as in FIG. 4 are given the same reference numerals.

In this embodiment, the reinforcing ribs 51 and 61 around the band-shaped hole 21 on one side and the outer periphery, with the vicinity of the hole 1 in the center as a boundary, and the reinforcing ribs 51 and 61 around the hole 1 in the center. As shown in box a, a portion of the reinforcing ribs 71 are attached to the upper surface of the sub-chassis, along with the reinforcing ribs 52 and 62 around and around the strip-shaped hole 22 on the other side, and the reinforcing ribs 52 and 62 around the hole 1 located in the center. A portion 72 of the surrounding reinforcing ribs is installed on the lower surface of the sub-chassis as shown in FIG. Moreover, when the height of the lip is set to the 5 to 12 side, deformation over time is small and the effect is large in terms of moldability. The first table shows the second
A molded product having the shape shown in Figures 4 and 5 was molded using unsaturated polyester containing 15% glass fiber and 60% inorganic filler based on the total weight. 1
Warpage Q when heating the bait for 40 hours and 1 at 90:00
The results of creep deformation when a load is applied to the center portion for 40 m hours are shown in comparison with the case without reinforcing ribs as shown in FIG.

- This table shows that the installation of reinforcing ribs significantly improves both the warp Q and cleave deformation.

Note that here, as shown in FIG. 6, the warp Q is defined by the following equation from the maximum concave amount y and the maximum convex amount 8. Q=8
10y……{11 In this case, twisting is included in warping.

That is, from the perspective of the shape, the embodiment shown in FIG. 4>the fifth embodiment.
Embodiments in the Figures> The dimensional accuracy becomes better in the order of the embodiments in FIG. 2, and similar results are obtained with respect to creep deformation. Below, when reinforcing ribs are arranged (for example, the second
The effect of (as shown in the figure) will be explained.

7 and 8 are shown for comparison; FIG. 7 shows the case where no reinforcing ribs are provided, and FIG. 8 shows the case where only the reinforcing ribs 5 around the band-shaped holes 2 are provided. In each case, a shows a plan view, and b shows a cross-section of A-A and B-B of a, respectively. In these figures, the same parts as in FIGS. 1, 2, and 4 are given the same reference numerals. That is, as shown in FIG. 7, when the reinforcing lip is not provided, the band-shaped void 2 is long, so
Residual stress caused by molding causes deformation in the region 8 surrounded by the band-shaped holes 2, and similar deformation occurs when a cylinder is mounted in the center. These deformations can be prevented by providing reinforcing ribs 53 around the band-shaped holes, as shown in FIG. 8, but with only these reinforcing ribs 53, the Deformation cannot be prevented. On the other hand, in the embodiment of the present invention, reinforcing ribs 5 and 6 are provided around and around the band-shaped hole 2, so that deformation as in the previous technique can be prevented.

However, if these reinforcing ribs 5 and 6 are installed independently, deformation occurs due to residual stress generated during the cooling process during molding. Therefore, in the embodiment, the reinforcing lips 5 and 6 are made continuous to prevent deformation. Table 2 shows the molded products having the shapes shown in Figure 1 (or Figure 7), Figure 8, and Figure 2, containing 15% glass fiber and 60% inorganic filler based on the total weight. This figure shows the change in warpage over time when molded from unsaturated polyester and heated at 90q0 for 140 hours.

From this table, it can be seen that the shape shown in FIG. 2 has particularly little deformation over time and good precision. In addition, when the reinforcing ribs are installed over the entire surface, the root part of the reinforcing ribs
Since the structure is as shown in FIG. b, the height of the flow path is high and the flow resistance is small, so that the resin can be quickly filled into the mold. In particular, because the flow resistance is small, the resin first fills the root part of the reinforcing lip,
Since the reinforcing ribs are then spread over the entire structure, the orientation of the glass fibers becomes more random than in the case where no reinforcing ribs are provided, and the anisotropy of the strength also decreases. Table 2, FIG. 9 shows yet another embodiment, and the same parts as in FIGS. 2 and 4 are given the same reference numerals. ~ Reinforcement ribs 73, 54, and 6 are installed independently around the periphery and outer periphery of the band-shaped hole 2, respectively, and these reinforcing ribs 73, 54, and 6 are connected by a separately provided reinforcing rib 9. , it is possible to obtain the same effect as the above embodiment.

Table 3 shows the relationship between the height of reinforcing ribs, deformation over time, and formability using the shape shown in Figure 2 as an example.
Results are shown after heating at 90 oo for 140 field hours.

Regarding moldability in this table, good properties are indicated by a circle, and cases where the mold is not filled or voids are formed are indicated by a triangle. Table 3 From this table, it can be seen that when the height is set to 5 or more ribs, the warpage becomes better.

On the other hand, if the height exceeds 12 ribs, it is undesirable because the mold will not be filled with resin or voids will occur. As described above, the VTR sub-chassis of the present invention is lightweight, has little deformation under light conditions, and is highly strong, making it possible to provide a VTR sub-chassis with great industrial effects.

[Brief explanation of the drawing]

FIG. 1 is a plan view schematically showing a subchassis for a VTR;
FIG. 2 is a plan view of an embodiment of the VTR subchassis of the present invention, FIG. 3 is an explanatory diagram of warpage and twisting, and FIG. 4 is a
A plan view of another embodiment of the VTR subchassis of the present invention,
Figures 5a and 5b are top and bottom views of other embodiments, Figure 6 is an explanatory diagram of the definition of warpage, and Figure 7a is a VTR without reinforcing ribs for comparison. FIG. 7b is a sectional view taken along the line A-A in FIG. 7a, and FIG. 8a is a plan view of a VTR subchassis in which reinforcing lips are provided only around the band-shaped holes. 8b is a sectional view taken along line BB in FIG. 8a, and FIG. 9 is a plan view of another embodiment of the VTR subchassis of the present invention. 1... Hole (located in the center), 2, 21,
22... Band-shaped holes, 5, 51, 52, 54... Reinforcement ribs (located around the band-shaped holes), 6, 61, 62... (
Reinforcement lips around the outside of the chassis, 7, 71, 72, 73.
... Reinforcement rib (around the hole located in the center), 9 ... Reinforcement rib. Younger brother/Figure 2 Figure 3 Figure 4 Figure 7 Figure 7 Figure 8 Figure 8 Shizuo Figure

Claims (1)

[Scope of Claims] 1. A cylinder, an audio head, and a mechanical member for mounting and running a magnetic tape thereon, a hole located in the center and penetrated by a bearing fixing part of the cylinder;
A sub-chassis for a video tape recorder having band-shaped holes located on both sides of the hole and guiding the guide base of the mechanism member, wherein the sub-chassis is made of a plastic molded body, and the guide base is arranged along the band-shaped hole. Reinforcing ribs are installed on one or both sides of the sub-chassis on the outside of the running area of the guide base and on the outer periphery of the sub-chassis, and these reinforcing ribs are mutually continuous in one plane and are installed on the top and bottom of the sub-chassis, respectively. A sub-chassis for a video tape recorder, characterized in that said reinforcing ribs surround the outside of a traveling area of said guide base and the outer periphery of said sub-chassis, with an overlapping portion when projected. 2 Among the reinforcing ribs, the reinforcing ribs installed around the band-shaped holes on one side and around the outer periphery of the sub-chassis, with the vicinity of the hole located in the center as a boundary, are installed on the top surface of the sub-chassis, and on the other side. The sub-chassis for a videotape recorder according to claim 1, wherein the reinforcing ribs installed around the band-shaped holes and around the outside of the sub-chassis are located on the lower surface of the sub-chassis. 3. The sub-chassis for a videotape recorder according to claim 1 or 2, wherein the reinforcing rib has a height of 5 to 12 mm. 4. A cylinder, an audio head, and a mechanical member for mounting and running a magnetic tape thereon, and a hole located in the center and penetrated by the bearing fixing part of the cylinder;
A sub-chassis for a video tape recorder having band-shaped holes located on both sides of the hole and guiding the guide base of the mechanism member, wherein the sub-chassis is made of a plastic molded body, and the hole is located in the center part, and the sub-chassis is made of a plastic molded body. Reinforcing ribs are installed on one side or both sides of the sub-chassis on the outside of the running area of the guide base where the guide base runs along the band-shaped holes and on the outer periphery of the sub-chassis, and these reinforcing ribs are mutually connected on one surface. When projected, the reinforcing ribs, which are installed on the upper and lower sides of the sub-chassis, surround the hole located at the center, the outside of the travel area of the guide vane, and the outer periphery of the sub-chassis, with overlapping parts when projected. A sub-chassis for video tape recorders that is characterized by: 5 Among the reinforcing ribs, the reinforcing ribs installed around the band-shaped holes on one side and around the outside of the sub-chassis, with the vicinity of the hole located in the center as a boundary, are installed on the top surface of the sub-chassis, 5. The sub-chassis for a video tape recorder according to claim 4, wherein the reinforcing ribs installed around the holes and around the outside of the sub-chassis are located on the lower surface of the sub-chassis. 6. The sub-chassis for a videotape recorder according to claim 4 or 5, wherein the reinforcing rib has a height of 5 to 12 mm.