JPH0663261U - Cylinder head valve seat rubbing tool - Google Patents

Abstract

(57) [Abstract] [Purpose] An object is to provide a valve seat rubbing tool for a cylinder head which is easy to use and can complete the work in one step. [Structure] A plurality of twist grooves for electrodepositing particles of cubic boron nitride and discharging chips on a surface 5e of a base metal 5a, which has a truncated cone shape and whose surface 5e contacts the valve seat surface of the cylinder head. 5 g was provided radially outward in a substantially radial manner.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a valve seat rubbing tool for a cylinder head.

[0002]

[Prior art]

 In the quality inspection of the cylinder head, if the valve seat is judged to be out of specification, it is necessary to rework such as rubbing work. For this small amount of valve seat rubbing work, manual work with a rubbing tool may be efficient. Figures 1 and 2 show this type of work in which a roughing rubbing tool 1 with a carbide cutter and a finishing rubbing tool 2 with a sandpaper are used. used. As shown in FIG. 1, a rubbing tool 1 including a carbide cutter includes a base metal 1a having a truncated cone shape, a shank 1b for supporting the base metal 1a, and a handle 1c attached to an upper end of the shank 1b. And a large number of super hard cutters 1 d are provided on the umbrella-shaped surface of the base metal 1 a.

Then, the worker mounts the base metal 1a with a carbide cutter on the shank 1b, and inserts the tip of the shank 1b into the valve guide hole 3c from the valve mounting portion opening 3a of the cylinder head 3 to mount the base. The surface of the gold 1a is joined to the valve seat surface 3b. Therefore, the handle 1c is operated to rotate the base metal 1a, and the valve seat surface 3b is processed by the cutting action of the cemented carbide cutter 1d. Then, as shown in FIG. 2, using the rubbing tool 2 for finishing, in which the sandpaper 2d is attached to the surface of the base metal 2a, the same procedure as that of the rubbing tool 1 for roughing is used. The valve seat surface 3b is finished to be smooth. It should be noted that the cylinder head 3 shown in FIGS. 1 and 2 is schematically shown, and the combustion chamber, pores and the like provided in the cylinder head 3 are omitted.

[0004]

[Problems to be solved by the device]

 By the way, the rubbing tool 1 with the cemented carbide cutter is difficult to use because the cuts of the cutter 1d are likely to be galling or chattering on the cut valve seat surface 3b. Therefore, skill is required in use. In addition, there is a disadvantage that it requires additional finishing work, which is troublesome twice.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a valve seat rubbing tool for a cylinder head that is easy to use and can complete the work in one operation.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, according to the present invention, cubic boron nitride particles are electrodeposited and cut on the surface of a base metal having a frustoconical surface whose surface contacts the valve seat surface of the cylinder head. A plurality of twist grooves for discharging the powder are provided radially outward in a substantially radial manner.

[0007]

[Action]

 The surface of the base metal is brought into contact with the valve seat surface of the cylinder head, the base metal is rotated, and the valve seat is ground. At this time, chips generated between the valve seat surface of the cylinder head and the surface of the base metal are discharged along the twist groove on the surface of the base metal. As a result, the valve seat surface of the cylinder head is machined at a smooth level that does not require a separate finishing operation due to the grinding action of each particle of cubic boron nitride nitride electrodeposited on the surface of the base metal.

[0008]

【Example】

 An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 3 shows a valve seat rubbing tool for a cylinder head according to the present invention. This valve seat rubbing tool 5 includes a base metal 5a made of alloy tool steel, a shank 5b for supporting the base metal 5a, and a shank 5b. And a bar-shaped handle 5c fixed to the upper end of the. The shank 5b and the handle 5c have a T-shaped integrated structure, and a taper liner 5d is fixed by a pin 6 at a predetermined position of the shank 5b. The surface of the taper liner 5d has a shape of a taper 1/20 that is reduced in diameter in the front end direction. The base metal 5a has a frustoconical shape made of alloy tool steel, and its size and surface are adjusted according to the size of the valve seat of the cylinder head to be rubbed and the cross sectional gradient of the valve seat surface. A slope A of 5e is determined. That is, when the sectional view gradient of the valve seat surface of the cylinder head to be worked is 45 degrees, the gradient A of the surface 5e of the base metal 5a is 45 degrees. A taper hole 5f into which a taper liner 5d fixed on the shank 5b is fitted is formed at the center of rotation of the base metal 5a. The taper hole 5f is closely attached to the surface of the taper liner 5d. Like the taper liner 5d, the taper liner 5d has a taper 20-minute diameter 1 in the front end direction.

On the surface 5e of the base metal 5a, an electrodeposition layer of particles of cubic boron nitride (CBN) that is hard and has high heat resistance is formed, and the cubic boron nitride particles that form this electrodeposition layer are formed. The grinding action grinds the valve seat surface of the cylinder head. For rubbing the valve seat surface of the cylinder head, particles with a particle size of about 1 to 100 μm can be used, but especially for particles with a particle size of about 30 μm, the working speed and the processed surface are smooth. It is preferable from the viewpoint of degree. When the above-mentioned electrodeposition layer is formed of cubic particles of boron boron nitride, the machining allowance increases and the working speed increases, but the smoothness of the processed surface decreases. Further, when the electrodeposited layer is formed of cubic boron nitride having a small particle size, the machining allowance is reduced and the working speed is reduced, but the smoothness of the machined surface is increased.

Further, as shown in detail in FIG. 4, the surface 5e of the base metal 5a is provided with a plurality of twist grooves 5g having a depth of about 1 mm for discharging chips, and these twist grooves 5g are provided. The grooves 5g are arranged substantially radially outward from the center of rotation of the base metal 5a, and the chips generated when the valve seat surface 3b of the cylinder head 3 is ground along these twist grooves 5g. It is supposed to be discharged.

The valve seat rubbing tool 5 for a cylinder head of the present invention is configured as described above and is used as follows. The worker mounts the base metal 5a on the shank 5b and inserts the tip of the shank 5b into the valve guide hole 3c from the valve mounting portion opening 3a of the cylinder head 3 in the same procedure as in FIG. The surface 5e of 5a is joined to the valve seat surface 3b. There, the handle 5c is operated to rotate the base metal 5a to grind the valve seat surface 3b in contact with the surface 5e of the base metal 5a by the grinding action of each of the hard and fine particles of cubic boron nitride. . Therefore, the valve seat surface 3b of the cylinder head 3 is processed at a smooth level that does not require a separate finishing process. At this time, the chips generated between the valve seat surface 3b of the cylinder head 3 and the surface 5e of the base metal 5a are discharged along each twist groove 5g formed on the surface 5e of the base metal 5a. Therefore, the chips do not remain between the valve sheet surface 3b and the surface 5e of the base metal 5a and deteriorate the grinding ability of the tool.

Further, the particles of cubic boron nitride have high heat resistance, and the rubbing operation is not easy in the past. For example, the rubbing operation of a valve seat made of stellite, a sintered material or the like can be done easily.

[0013]

[Effect of device]

 As described above, according to the present invention, the particles of cubic boron nitride are electrodeposited on the surface of the base metal, which has a truncated cone shape and the surface of which is in contact with the valve seat surface of the cylinder head, and the cutting powder. Since a plurality of twist grooves to be discharged are provided radially outward in a substantially radial manner, the work is facilitated and the work can be completed in one step, and the efficiency of the valve seat rubbing work is improved. Can be improved. Further, since the heat resistance is improved, it is possible to easily perform the rubbing operation of the valve seat, which is not easy in the conventional rubbing operation of, for example, stellite or a sintered material.

[Brief description of drawings]

FIG. 1 is a diagram showing an operation using a valve seat rubbing tool of a cylinder head having a conventional cemented carbide cutter.

FIG. 2 is a diagram showing a work using a valve seat rubbing tool of a cylinder head provided with a conventional sand paper.

FIG. 3 is a view showing a valve seat rubbing tool for a cylinder head of the present invention.

FIG. 4 is a view on arrow IV in FIG.

[Explanation of symbols]

 3 Cylinder head 3b Valve seat 5 Cylinder head valve seat rubbing tool 5a Base metal 5e Surface 5g Twist groove

Claims (1)

[Scope of utility model registration request] 1. A plurality of twists in which particles of cubic boron nitride are electrodeposited and chips are discharged onto the surface of a base metal having a truncated cone shape whose surface contacts the valve seat surface of the cylinder head. A valve seat rubbing tool for a cylinder head, characterized in that grooves are provided substantially radially outward.