JPH046497B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a mold polishing device used for smoothing the free-curved surface of a mold having a free-curved surface after rough machining and further mirror-finishing it. be.

Conventional technology The production of molds with free-form surfaces is roughly divided into rough processing using a machine tool such as a copy milling machine or machining center, smoothing processing using a hand glider, etc., and mirror polishing processing using an oil grindstone. is normal.

As for rough machining, highly automated machine tools are used, so it is possible to perform highly efficient automatic machining on various free-form surfaces. On the other hand, polishing and mirror polishing of free-form surfaces are difficult to automate and rely on manual finishing, and there is a strong demand for automation.

For gently curved surfaces such as those of television cathode ray tubes, some automatic polishing devices have been put into practical use that perform constant-pressure polishing using the reciprocating motion of an oil grindstone. An example of this will be explained below with reference to FIG. In Fig. 3, 1 is a polishing workpiece with a gently curved surface such as a television cathode ray tube, and 2 is a part of the polishing device main body, which is automatically reciprocated in the horizontal or vertical direction of the paper by another drive device (not shown). controlled to perform. Reference numeral 3 denotes a cylinder using air or oil as a working medium, and by introducing a pressure medium from the outside, a constant pressing force 4 in the vertical direction (in the direction of the arrow) is applied to the rod 5.
An oil grindstone 7 is connected to the tip of the rod 5 via a rotation fulcrum 6, and polishing is performed by relative movement between the oil grindstone 7 and the workpiece 1.

The feature of the above-mentioned device is that the oil grindstone 7 is pressed against the workpiece 1 under constant pressure via the rotation fulcrum 6 to perform polishing, so the oil grindstone 7 polishes while following the shape of the pre-processed surface of the workpiece 1. It is at the point where it is done. Another feature is that even if the oil grindstone 7 is worn out, it is always ground under constant pressure due to the constant pressing force 4 of the cylinder 3.

Problems to be Solved by the Invention However, the above-mentioned conventional devices can only handle extremely gently curved surfaces such as those of cathode ray tubes in televisions, and polishing is dependent on reciprocating motion, resulting in low efficiency. However, there were problems in that it was difficult to supply the polishing liquid between the grinding wheel and the workpiece, and the polishing debris sometimes caused damage to the workpiece, leading to deterioration of the quality of the mold.

Therefore, it has been proposed that a polishing object made of an elastic material is filled with fluid and brought into close contact with the polishing surface of the mold for polishing, but with these methods, clogging of the polishing object is unavoidable. However, there was a problem with poor polishing efficiency.

Means for Solving the Problems The present invention was proposed in view of the above-mentioned problems of the conventional apparatus, and a polishing shaft is attached to a main body that is relatively movable along the polishing surface of a mold through a housing. A mold polishing device supported movably in the direction and applying polishing pressure by a fluid pressure applying means, having an expanded portion at the tip, constantly supplying polishing liquid into the expanded portion, In addition, it has a polishing shaft that is rotationally driven by a motor and a large number of fine through holes on the entire surface, and the polishing material is evenly distributed and adhered to the entire surface, and the periphery is stretched and fixed to the expanded part at the tip of the polishing shaft. It is characterized by comprising a water-permeable flexible membrane which is bulged out in a spherical shape by the hydrostatic pressure of the polishing liquid supplied to the expanded portion of the polishing shaft and can flexibly follow and adhere to the polishing surface of the mold. It is something to do.

Function: When the grinding fluid is supplied, a uniform hydrostatic pressure is generated in each part of the expanded part at the tip of the polishing shaft due to the water permeation resistance of the water permeable flexible film, and the water permeable flexible film protrudes into a spherical shape, resulting in machining. It is possible to freely follow and adhere to the shape of the mold, which is the object, and as a result, using this hydrostatic pressure and the fluid pressure of the fluid pressure applying means, it is possible to polish the surface with equal pressure, improving polishing accuracy. can be improved.

In addition, since grinding fluid is constantly ejected from inside the water-permeable flexible membrane, polishing debris does not accumulate inside the contact surface between the water-permeable flexible membrane and the workpiece, and the polishing debris on the mold surface This can prevent damage and clogging of the water-permeable flexible membrane.

Embodiment FIG. 1 is a longitudinal sectional side view of a main part showing an example of the apparatus of the present invention, and FIG. 2 is an explanatory side view showing an example of its operating state. In FIG. 1, 11 is a polishing shaft;
2 is a water-permeable flexible membrane; 13 is a housing; 14 is a main body; 15 is a cylinder serving as a means for applying fluid pressure; 16
17 indicates a motor, and 17 indicates a fluid coupling.

The polishing shaft 11 has an expanded portion 11a at its tip, and has a through hole 11b so that grinding fluid can be constantly supplied toward the expanded portion 11a, and the rear end is connected to the motor 1.
6 via a fluid coupling 17, and the housing 1
The fluid coupling 17 is rotatably supported at two locations within the fluid coupling 3 via bearings 18, 18.
It is connected to a grinding fluid supply pump (not shown) via a hose.

The water-permeable flexible membrane 12 has fine holes 12a on the entire surface.
[Depending on the membrane manufacturing method, a wide variety of pores can be formed.
A fibrous membrane such as a textile has a large number of pores formed by gaps between fibers, and an abrasive material 12b such as an electrodeposited grindstone is evenly distributed over the entire surface.
Its periphery is stretched and fixed to the expanded portion 11a at the tip of the polishing shaft 11 via a presser ring 19 with screws 20.

The housing 13 rotatably supports the polishing shaft 11 via bearings 18, 18.
Within the main body 14, it is movable in the axial direction of the polishing shaft 11 and is supported so as not to rotate (rotation stop mechanism not shown).

The main body 14 is attached to the main shaft of a copy milling machine or the main shaft of an NC-controlled machine tool such as a machining center, and is rotated relative to the table on which the mold is mounted based on model copying or NC data along the polished surface of the mold. It is said to be movable.

The cylinder 15, which is a fluid pressure applying means, is installed between the housing 13 and the main body 14.
In the embodiment shown in FIG.
is shown, but the invention is not limited to this. Air pressure or oil pressure is applied inside the cylinder 15, and a certain pressure is applied to the polishing shaft 11 toward the distal end side.

The device of the present invention has the above configuration, and its operation will be explained next.

First, the polishing shaft 11 is moved to a mold polishing starting point by the moving means of the main body 14, and supply of the grinding fluid is started at this position. Further, in parallel with this, the motor 16 rotates, and fluid pressure is supplied to the cylinder 15 of the fluid pressure applying means.

The grinding fluid is supplied from the fluid coupling 17 to the expanded portion 11a of the polishing shaft 11, passes through the water-permeable flexible membrane 12, and is discharged to the outside. In this case, the water permeable flexible membrane 1
When the grinding fluid passes through the through holes 12a of No. 2, the pressure of the grinding fluid itself and the fluid resistance when the grinding fluid passes through the through holes 12a work to balance each other, and as a result, the water permeable flexible membrane The interior of the tube 12 is in the same state as if a uniform hydrostatic pressure were applied thereto, and it protrudes into a spherical shape as shown in FIG.

The water-permeable flexible membrane 12 has an abrasive material 12b uniformly distributed over the entire surface, and the polishing shaft 11
is rotated by the motor 16, and pressure force is applied to the polishing shaft 11 against the mold surface by the fluid pressure applying means 15, so that polishing can be performed while deforming to follow the mold surface. I can do it. In order to apply polishing pressure to the mold surface, fluid pressure applying means 1 is used.
5 and the hydrostatic pressure within the water-permeable flexible membrane 12 of the grinding fluid act simultaneously, and the main body 14 is moved in a state where both pressures are balanced [the balanced state can be adjusted by the pressures of both]. By doing so, polishing can be performed while tracing the surface shape of the mold.

FIG. 2 shows the polishing state when the mold 21 has a free-form surface 21a, and shows the water permeable flexible membrane 12.
Due to the hydrostatic pressure of the grinding fluid, the free-form surface 2 of the mold 21
By simultaneously rotating the main body 14 in close contact with the surface shape of 1a, by moving the main body 14 in the direction of the arrow 22 [including linear movement only or a combination of linear movement and reciprocating movement] using an appropriate moving means [not shown]. Automatic copy polishing of the entire surface of the mold 21 becomes possible.

Effects of the Invention According to the present invention, by using a water-permeable flexible membrane, it is possible to flexibly follow and closely adhere to the free-form surface shape often found in molds, and perform polishing. Moreover, a uniform polishing pressure can be applied to the free-form surface shape of the mold by the hydrostatic pressure of the grinding fluid, and the amount of polishing of each part becomes uniform, improving the polishing accuracy of the mold.

Furthermore, the water-permeable flexible membrane allows the polishing surface of the mold to be directly polished by uniformly distributing and adhering the polishing material over the entire surface, but during this polishing operation, the polishing fluid is constantly spread. Since it is ejected from inside the opening to the outside, adhesion of grinding debris and clogging can be prevented, and good grinding can always be performed.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional side view of the main part showing an example of the apparatus of the present invention, FIG. 2 is an explanatory side view showing an example of its operating state, and FIG. 3 is a schematic side view showing an example of a conventional free-form surface polishing apparatus. It is. 11... Polishing shaft, 12... Water-permeable flexible membrane, 13
... Housing, 14 ... Main body, 15 ... Fluid pressure applying means, 16 ... Motor, 12a ... Through hole, 1
2b...Abrasive material.

Claims (1)

[Claims] 1. A polishing shaft is movably supported in the axial direction via a housing in a main body that is relatively movable along the polishing surface of a mold, and a polishing pressure is applied by a fluid pressure applying means. The mold polishing device has a polishing shaft that has an expanded portion at the tip, constantly supplies polishing liquid into the expanded portion, and is rotated by a motor, and a fine through hole on the entire surface. The abrasive material is distributed uniformly over the entire surface, the periphery is stretched and fixed to the widened part of the polishing shaft, and the hydrostatic pressure of the polishing liquid supplied to the widened part of the polishing shaft is applied. A mold polishing device characterized by comprising a water-permeable flexible membrane that protrudes into a spherical shape and can flexibly follow and adhere to the polishing surface of a mold.