JPH11188644A - Cut type grinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cup type grinder preventing grinding fluid from remaining inside the grinder. SOLUTION: This grinder is provided with a cup type metal base 2 having a peripheral wall part 2b, an abrasive grain layer segment 6 arranged at the lower end of the peripheral wall part 2b in an annular shape, a fluid receiving recessed part 14 formed at the upper end surface of the metal base 2, and a number of fluid feeding holes 16 whose one end is opened at the inner bottom surface 14b of the fluid receiving recessed part 14 and whose other end is opened at a more inward side than the peripheral wall part 2b of a base metal lower surface. The fluid feeding hole 16 is formed at such an angle as to go outwards in the radial direction of the metal toward downwards from above, and the fluid feeding hole 16 has such a taper shape that a passage cross section reduces downwards from the above.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cup-type grindstone used for various types of surface grinding.

[0002]

2. Description of the Related Art A general cup-shaped grindstone is formed by fixing a large number of curved rectangular parallelepiped abrasive grain layer segments on one end surface of a cup-shaped base along a circumference centered on the base metal axis. And is used for various types of surface grinding.

When wet grinding is performed using a cup-type grindstone of this type, it is important to efficiently and uniformly supply a grinding fluid to a grinding portion (a friction portion between a work material and an abrasive layer). Therefore, in general, a method of forming a liquid supply path inside the rotating shaft and supplying the grinding liquid from the inside of the base metal is adopted. However, in this case, there is a disadvantage that the structure of the grinding device is complicated because a liquid supply path must be formed in the rotating shaft.

In order to avoid the necessity of forming a liquid supply passage on the rotating shaft, Japanese Patent Application Laid-Open Nos. Hei 6-23673 and Hei 6-23674 disclose an annular groove formed on the upper surface of a cup-shaped base. A cup-type grindstone has been proposed in which a grinding fluid introduction hole is formed which opens from the inner bottom surface of the annular groove to the inside of the peripheral wall of the base metal. According to such a cup-shaped grindstone, by pouring the grinding fluid from the outside of the grindstone into the annular groove during grinding, the grinding fluid is uniformly discharged to the inside of the base metal through the introduction hole by gravity and centrifugal force. The same effect as in the case where the grinding fluid is supplied through the rotating shaft can be obtained.

[0005]

By the way, in the cup-type grindstones described in the above publications, the grinding fluid discharged inside the base metal is difficult to be discharged outside from the gap between the abrasive grain layer segments, so that the grinding wheel There is a problem that it collects inside and affects the balance of the grinding wheel rotation. The present inventors examined the above problem in detail, and found that the conventional cup-type grindstone has a weak force to discharge the grinding fluid downward in the grindstone, and the centrifugal force of the grindstone causes the grinding fluid flow to generate a vortex. It was found that this was due to rising inside the whetstone.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a cup-type grindstone in which a grinding fluid does not easily accumulate in a grindstone.

[0007]

In order to solve the above-mentioned problems, a cup-type grindstone according to the present invention is provided with a cup-shaped base having a peripheral wall, and an annular arrangement at the lower end of the peripheral wall of the base. An abrasive grain portion, a liquid-receiving concave portion formed on the upper end surface of the base metal, and one end opened at the inner bottom surface of the liquid-receiving concave portion and the other end is located on the inner peripheral side of the peripheral wall portion of the lower surface of the base metal. A liquid supply hole that is opened, the liquid supply hole is formed at an angle directed outward from the base metal in the base metal direction from above to below, and at least a part of the liquid supply hole is formed from above to below. It is characterized in that the cross-sectional area of the flow path is reduced.

According to such a cup-shaped grindstone, when the grinding fluid supplied to the liquid receiving recess flows into the liquid supply hole extending downward and outward, the grinding fluid is propelled by the centrifugal force accompanying the rotation of the grinding wheel. While flowing down the inside of the liquid supply hole. At that time, since the inner wall surface of the liquid supply hole has a tapered shape narrowing downward, the speed of the grinding fluid increases as the liquid supply hole is lowered, and eventually the diagonal downward from the lower end of the liquid supply hole. It is released vigorously. Therefore, the grinding fluid quickly flows out through the gap between the abrasive grains while maintaining the momentum.

[0009]

1 and 2 are a vertical sectional view and a bottom view showing a first embodiment 1 of a cup-type grindstone according to the present invention. The cup-shaped grindstone 1 of this embodiment includes a cup-shaped base 2 composed of a disk-shaped top plate 2a and a peripheral wall 2b hanging down from the outer periphery of the top plate 2a.
An annular groove 4a is formed coaxially with the base metal 2 on the lower end surface 4 of the peripheral wall portion 2b, and a plurality of abrasive grain layer segments (abrasive grain portions) 6 are arranged in a line at equal intervals in the groove 4a. It is fitted and fixed. Note that “up and down” used in this description does not limit the usage mode of the cup-type grindstone 1.

On the upper end surface of the base metal 2 is formed a liquid-receiving recess 14 which is formed in an annular shape coaxial with the base metal axis. The liquid receiving concave portion 14 has a substantially U-shaped cross section having an outer peripheral side surface 14a, an inner bottom surface 14b, and an inner peripheral side surface 14c, and the outer peripheral side surface 14a is an inclined surface extending radially outward from above to below. The bottom surface 14b is a horizontal surface, and the inner peripheral side surface 14c is a vertical surface.

When the outer peripheral side surface 14a is inclined as described above, the grinding fluid supplied into the liquid receiving recess 14 is propelled downward along the outer peripheral side surface 14a by the centrifugal force of the rotation of the grinding wheel.
A pressure toward the outer peripheral bottom surface of the liquid receiving recess 14 is generated. Therefore, it is possible to prevent the grinding liquid from overflowing from the liquid receiving recess 14 and spilling out. The angle formed by the outer peripheral side surface 14a and the grinding wheel axis is not limited, but is preferably 10 to 45 °, and more preferably 20 to 40 °. If the angle α is too large, it is difficult to secure the opening width of the liquid-receiving concave portion 14, and if the angle α is too small, the grinding fluid supplied into the liquid-receiving concave portion 14 is centrifugally generated by the rotation of the grinding wheel.
This is because it is easy to jump out from the outside.

In this embodiment, the inner bottom surface 14b is formed as a horizontal surface. However, if necessary, the inner bottom surface 14b may be formed as an inclined surface which is inclined downward toward the outside in the grinding wheel radial direction. With such an inclination, the grinding fluid supplied into the liquid receiving concave portion 14 is propelled toward the outer peripheral side along the inner bottom surface 14 b by gravity, and generates pressure toward the outer peripheral side bottom surface of the liquid receiving concave portion 14. This is because the liquid flows into the liquid supply hole 16 at a higher pressure.

The base metal 2 is provided on the inner bottom surface 14b of the liquid receiving recess 14.
A large number of liquid supply holes 16 are formed at regular intervals in the circumferential direction, and the lower ends of these liquid supply holes 16 reach the boundary between the top plate 2a on the back surface of the base metal 2 and the peripheral wall 2b. The openings are arranged as shown. These liquid supply holes 16 are formed at an angle that spreads outward in the base metal radial direction from the upper side to the lower side, and have a conical shape (tapered shape) in which the flow path cross-sectional area decreases from the upper side to the lower side. In this embodiment, the liquid supply hole 16 has a tapered shape over the entire length, but instead, a configuration in which only a part of the entire length is tapered may be employed. For example, the upper or lower part of the liquid supply hole 16 may be a simple cylindrical surface.

The angle α between the axis of the liquid supply hole 16 and the axis of the grinding wheel is not limited, but is preferably 10 to 45 °, more preferably 15 to 30 °. Within such a range, acceleration of the grinding fluid by centrifugal force is appropriate, and formation of the fluid supply hole 16 is also easy.

At the same time as the liquid supply hole 16 is inclined outward, the liquid supply hole 16 may be inclined in a direction having a helical angle in a direction opposite to the direction of rotation of the grindstone from the top to the bottom. This is because, when the cup-shaped grindstone 1 has such a spiral angle, a downward thrust is generated in the grinding fluid in the fluid supply hole 16 due to the rotation of the cup-shaped grindstone 1, and the pressure at which the grinding fluid is jetted increases.

The taper angle β of the liquid supply hole 16 is not limited, but is preferably 15 to 45 °, and more preferably 20 to 40 °. With such an angle range, the jet pressure of the grinding fluid is appropriate, and the
Is also easy to form.

Although the number and the opening diameter of the liquid supply holes 16 are not limited, an appropriate diameter and number are set so that the grinding liquid can be supplied uniformly over the entire circumference of the base metal 2 and the strength of the base metal 2 is not impaired. Should be selected. Generally, the opening diameter of the lower end of the liquid supply hole 16 is preferably about 2 to 4 mm, and the arrangement pitch of the liquid supply holes 16 in the circumferential direction of the grindstone is preferably about 7 to 15 mm.

On the upper surface 2a of the base metal 2, a liquid receiving recess 14 is also provided.
A plurality of mounting holes 12 spaced apart in the circumferential direction are formed on the inner peripheral side, and can be mounted on an upper surface plate of a grinding device (not shown) via these mounting holes 12. The liquid receiving concave portion 14 is formed at a position not closed by the upper platen. However, the mounting structure of the base 2 is not limited in the present invention. For example, a structure in which the base 2 is sandwiched between flanges without forming the mounting holes 12 may be used.

In this embodiment, the inner peripheral surface 8 of the peripheral wall 2b
Is an inclined surface that extends outward from the upper side to the lower side in the grinding wheel axial direction. Although the present invention is not limited to this configuration, by forming such an inclined surface 8, the grinding fluid discharged to the inner peripheral side of the peripheral wall portion 2 b moves downward along the inclined surface 8 due to centrifugal force accompanying the rotation of the grinding wheel. Therefore, it is possible to prevent the excessive grinding fluid from being accumulated inside the base metal 2 in combination with the strong momentum ejected downward from the liquid supply hole 16.

Although the angle between the inclined surface 8 of the peripheral wall 2b and the axis of the grinding wheel is not limited, it is preferable that the inclined surface 8 also has the same angle as the inclination angle α of the axis of the liquid supply hole 16. . In this case, the progress of the grinding fluid is not hindered by the inclined surface 8, and the grinding fluid can be directly sprayed to the grinding location by the abrasive grain layer segment 6 or slightly to the inner peripheral side. The fixed position of the abrasive grain layer segment 6 is set so that the grinding fluid discharged from the lower end of the liquid supply hole 16 is sprayed to the grinding location by the abrasive grain layer segment 6 or to a position slightly inner than that. Is preferred.

The abrasive grain layer segment 6 is conventionally used.
It may be formed of any material. Sand
, Super abrasive grains such as diamond and CBN or Si
C, Al _TwoO_ThreeMetal with general abrasive grains such as hardened with metal binder
The abrasive grains may be a bond abrasive layer, or the abrasive grains may be bonded to various resin.
It may be a resin bond abrasive layer hardened with a mixture,
Vitrified bond where the above abrasive grains are hardened with glass binder etc.
An abrasive layer may be used, or the abrasive may be fixed with an electrodeposited metal.
It may be an electrodeposited abrasive layer or an electroformed abrasive layer. Abrasive
The size and shape of the layer segment 6 are not limited. Also the groove
The abrasive layer segment 6 is directly applied to the end face 4 without forming the
It is good also as a structure which attached C.

According to the cup-shaped grindstone having the above structure,
The grinding liquid supplied into the liquid receiving recess 14 during the grinding enters the liquid supply hole 16 largely opened in the inner bottom surface 14b, and flows downward in the liquid supply hole 16 while being propelled by the centrifugal force caused by the rotation of the grindstone. At this time, since the inner wall surface of the liquid supply hole 16 has a tapered shape narrowing downward, the speed of the grinding fluid rapidly increases as the liquid supply hole 16 is lowered.
Are released from the lower end of the device diagonally downward. Since the released grinding fluid quickly flows out through the gap between the abrasive grain layer segments 6 while maintaining the momentum, the grinding fluid is unlikely to stay inside the cup-shaped grindstone 1 and the grinding wheel is rotated by the retention of the grinding fluid. Can be prevented.

At the same time, since the grinding fluid is sprayed at a high speed on the grinding portion, a high chip removing effect and a high cooling effect can be obtained. Furthermore, since the jet-shaped grinding fluid flow vigorously discharged from the fluid supply hole 16 suppresses the generation of the vortex flow of the grinding fluid inside the cup-shaped grindstone 1, the grinding fluid also flows from the inside of the cup-shaped grindstone 1. The effect of preventing stagnation is obtained.

[Second Embodiment] FIG. 3 is a longitudinal sectional view showing a second embodiment of the present invention. In this embodiment, the mounting surface 18 on the inner peripheral side of the liquid receiving recess 14 of the base metal 2 is
It is characterized by being displaced downward while maintaining the parallelism. Although the displacement amount H is not limited, for example, 1 to 5
mm.

By lowering the mounting surface 18 below the base metal upper surface 20 in this manner, the upper end of the outer peripheral side surface 14a of the liquid receiving recess 14 comes to a position higher than the mounting surface 18, so that the grinding to spread by centrifugal force is performed. The action of receiving the liquid by the outer peripheral side surface 14a is increased. Therefore, it becomes easy to efficiently supply the grinding liquid into the liquid receiving recess 14. In order to obtain the same effect as described above, it is also possible to form an annular wall portion on the upper surface of the grindstone so as to extend the outer peripheral side surface 14a.

Third Embodiment FIG. 4 is a longitudinal sectional view showing a third embodiment of the present invention. In this embodiment, the outer peripheral side surface 14a is a concave curved surface curved in the grinding wheel axial direction over the entire circumference. When the outer peripheral side surface 14a is curved in this manner, the grinding liquid is less likely to spill out of the liquid receiving concave portion 14. The inner bottom surface 14b can be curved.

Fourth Embodiment FIGS. 5 and 6 are a vertical sectional view and a bottom view showing a fourth embodiment of the present invention. This embodiment is characterized in that a fin 24 having a spiral shape centered on the grindstone axis is formed on the inner peripheral surface 8 of the base metal peripheral wall portion 2b.

The spiral fin 24 protrudes from the inclined surface 8 and is inclined at a substantially constant spiral angle so as to be displaced rearward in the direction of rotation of the grinding wheel from above to below the grinding wheel axis. The spiral fin 24 may be formed integrally with the base metal 2 or may be formed as a separate body and fixed to a predetermined portion of the base metal 2 by welding or the like. When such a spiral fin 24 is formed, the grinding fluid inside the base metal 2 is propelled downward as the grindstone rotates, so that the grinding fluid is prevented from staying inside the cup-type grindstone 1. Becomes stronger.

The present invention is not limited to the embodiments shown in FIGS. 1 to 6, and the configurations of these embodiments may be appropriately combined. Further, the present invention is employed in a conventional cup-type grindstone. Other configurations can be combined.

[0030]

As described above, according to the cup-type grindstone according to the present invention, when the grinding fluid supplied to the liquid receiving recess flows into the liquid supply hole extending downward and outward, the grinding wheel rotates. The grinding fluid flows downward in the liquid supply hole while being propelled by the accompanying centrifugal force. At that time, since the inner wall surface of the liquid supply hole has a tapered shape narrowing downward, the speed of the grinding fluid increases as it goes down the liquid supply hole, and eventually the diagonal downward from the lower end of the liquid supply hole. It is released vigorously. As a result, the grinding fluid quickly flows out through the gap between the abrasive grains while maintaining its momentum, so the grinding fluid is less likely to stay inside the base metal, preventing the grinding fluid from affecting the grinding wheel rotation. In addition, since the grinding fluid is supplied to the grinding section at a high speed, a high chip removal effect and a high cooling effect can be obtained. In addition, the jet-shaped grinding fluid flow vigorously discharged from the liquid supply hole has an effect of suppressing the generation of a vortex inside the base metal, and from this point, the grinding fluid is unlikely to stay inside the base metal. .

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment of a cup-type grindstone according to the present invention.

FIG. 2 is a bottom view of the first embodiment.

FIG. 3 is a longitudinal sectional view showing a second embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing a third embodiment of the present invention.

FIG. 5 is a longitudinal sectional view showing a fourth embodiment of the present invention.

FIG. 6 is a bottom view of the fourth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cup type grindstone 2 Base metal 4 End surface 4a Groove 6 Abrasive grain layer segment 8 Inclined surface 10 Center hole 12 Mounting hole 14 Liquid receiving recess 14a Outer peripheral side surface 16 Liquid supply hole 18 Mounting surface 20 Base metal upper surface 24 Spiral fin

Claims (3)

[Claims] 1. A cup-shaped base metal having a peripheral wall portion, abrasive grains arranged annularly at a lower end of the peripheral wall portion of the base metal, a liquid receiving recess formed on an upper end surface of the base metal, A liquid supply hole having one end opened on the inner bottom surface of the liquid receiving concave portion and the other end opened at a position on the inner peripheral side of the peripheral wall portion on the lower surface of the base metal, and the liquid supply hole is directed downward from above. A cup-shaped grindstone, wherein at least a part of the liquid supply hole has a shape in which a cross-sectional area of the flow path decreases from above to below. . 2. An inner peripheral surface of the peripheral wall portion is an inclined surface extending outward from upward to downward, and an outer peripheral side surface of the liquid receiving concave portion is an inclined surface extending outward from upward to downward. The cup-shaped grindstone according to claim 1, wherein: 3. A spiral fin is formed on an inner peripheral surface of the peripheral wall portion.
The described cup-shaped whetstone.