JPH0729242B2 - Cylindrical sleeve port groove processing equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rotary valve sleeve as a control valve for switching a working fluid circuit and controlling pressure in a power steering apparatus (power steering) for an automobile or the like. The present invention relates to a cylindrical sleeve port groove processing device for processing a port groove.

[Conventional technology]

The rotary valve in the power steering functions to detect the steering wheel turning angle as a steering input and control the hydraulic pressure to the output power cylinder according to the input. This type of rotary valve comprises a valve core 1 and a cylindrical sleeve (hereinafter, referred to as a valve sleeve) 2 as shown in FIGS. 6 and 7, and the valve sleeve 2 usually has a cylindrical inner surface 6 A cross-section spline axial valve core 1 having 6 sleeve port grooves 3 and usually 6 core port grooves 4 swings in a valve sleeve 2 as indicated by arrows (a) and (b). Thus, the inflow and outflow directions of the hydraulic fluid are controlled. In addition, 5 is a valve shaft as an input shaft integrally formed with the valve core 1, 6 is a housing, and 7 is a bearing. That is, when the valve core 1 swings in the clockwise direction (a) through the valve shaft 5 by turning a handle (not shown), the hydraulic fluid entering from the fluid inlet port 8 out of the core port groove 4. It is introduced into the sleeve / port groove 3a through the hydraulic groove 4a and pressurizes one cylinder chamber of the power cylinder (not shown). Valve sleeve 2 at the same time
The fluid in the port groove 3b of the
Then, the pressure is released to the outside through the piston of the power cylinder, and the pressure in the other cylinder chamber on the opposite side is released.

When the valve core 1 is swung in the counterclockwise direction (b) by operating the handle, the hydraulic groove 4a of the valve core 1 and the port groove of the valve sleeve 2 are moved.
3b is turned on. At the same time, the outflow groove 4b of the valve core and the port groove 3a of the valve sleeve are electrically connected. Thus, this rotary valve functions as a four-way valve and controls the hydraulic pressure to the power cylinder.

Examples of the conventional port groove structure of the sleeve of the rotary valve that functions in this manner include those shown in FIGS. 8 and 9. FIG. 8 shows that after a plurality of slots along the axial direction are formed on the inner surface of the valve sleeve 2 by broaching or the like, undercuts are provided on both end shoulders of the slots, and the step portion is tempered. The ring 9 is press-fitted to form the sleeve port groove 3 with both ends closed.

However, in the case where both ends of the port groove are closed by fitting the ring 9 in this way, there is a risk of disassembling if it is a little too loose due to its fitting tolerance, and conversely if it is too hard, distortion may occur in the outer circumference of the sleeve. However, there are many difficulties in its manufacture.

The one shown in FIG. 9 has been proposed to solve the above-mentioned difficulties (Japanese Patent Publication No. 49-49541). The sleeve / port groove 3 of the valve sleeve 2 is formed as a port groove with its groove end closed in the longitudinal direction by carving the groove bottom 10 into an arc shape as shown in the drawing. There is no problem based on such a fitting structure.

Port groove 3 having groove bottom 10 forming this arcuate bottom surface
As shown in FIG. 10, the inner wall Wa of the workpiece is cut by the cutter 11 which makes a circular motion (c) in a circular arc at a high speed in the inner passage of the workpiece W (hereinafter referred to as "work"). It is formed by The depth of the deepest part of the groove after completion is, for example, about 2 mm, and the cutting is repeated 40 times with a depth of 0.05 mm each time. Therefore, the work W is also oscillated (d) in association with the movement of the cutter 11 at each cutting operation.
That is, the inner wall of the work is moved by the complex relative movement of the swing motion (c) of the cutter 11 and the swing motion (d) of the work W.
Let us draw the motion trajectory of the cutter 11 as shown in Fig. 11 with respect to Wa. Numerals 11a, 11b, 11c ... Are cutting loci of the cutter 11 which are gradually deepened each time, and numeral 12 is a constant and substantially linear cutter return locus. In this case, since only one port groove can be cut in one cycle for one work W, the work is indexed and rotated after completion of each one according to the number of port grooves (usually 6), and the remaining (5 Sequentially cut the port groove of (book).

[Problems to be Solved by the Invention]

However, in such conventional port groove processing of a rotary valve sleeve, the cutter is oscillated, and at the same time, the work is also oscillated, whereby the work is gradually cut by the cutter. Therefore, the processing equipment was extremely complicated based on the combination of the cam and the crank. And also 1 sleeve port groove
There is a problem that it takes time to process because it is finished one by one.

The present invention has been made in view of such conventional problems, and provides a cylindrical sleeve port groove processing device in which only a cutter is oscillated to easily process a port groove. The purpose is to solve the above problems.

[Means for Solving the Problems]

Therefore, in the cylindrical sleeve port groove machining device according to the present invention, one end of the crank arm slidably inserted in the slide receiving member having the swing fulcrum is engaged with the crank pin of the crank device. A groove cutter driving device that moves the groove cutter holding portion provided on the other end of the crank arm in an approximately elliptical shape by rotation, and a cylindrical sleeve processing material that processes the sleeve port groove on the inner surface to the groove cutter holding portion. And a workpiece holding device for rotating and holding the sleeve-working material by a predetermined angle when one step of the groove processing of the sleeve port is completed by the approximately elliptic movement of the groove cutter attached correspondingly and attached to the groove cutter holding portion. A cylindrical sleeve port groove processing apparatus, wherein the sleeve port groove processing is performed by increasing the cutting amount by the approximate elliptical movement of the groove cutter holding portion. With the configuration characterized by comprising a cutting depth slightly means for advancing and is intended to achieve the above object.

Further, in the above structure, the groove cutters are attached to both sides of the groove cutter holding portion of the crank arm, and when the crank arm slides forward, one groove cutter is used, and when the crank arm is returned, the other groove cutter is used. A structure in which sleeve port grooves are formed on both opposing inner surfaces of the sleeve material.

Further, in the above structure, the cutting depth slightly increasing means increases the turning radius of the crank pin with which one end of the crank arm provided in the crank device is engaged to increase the cutting amount by the approximate elliptical movement of the groove cutter holding portion. A configuration characterized by:

Further, in the above-mentioned configuration, the cutting depth slightly increasing means moves the arrangement position of the slide receiving member having the rocking fulcrum for rocking and slidably supporting the inserted crank arm to the crank device side to move the groove cutter. The above-described object is also achieved by a configuration characterized in that the amount of cutting by the movement of the holding portion in an approximate elliptical shape is increased.

〔Example〕

Hereinafter, a cylindrical sleeve port groove processing device according to the present invention will be described with reference to the drawings.

FIGS. 1, 2, and 3 are diagrams showing an embodiment of this explanation. On the bed 20, a groove cutter driving device 21 for cutting the port groove of the work W and a work holding device 40 for fixedly holding the work W are attached.

The groove cutter driving device 21 is configured as follows. twenty two
Is a crank device, a crank shaft 23, a crank pin 24 that is eccentric with respect to this shaft by a crank radius R, a crank arm 25 whose one end is supported by this crank pin, a pulley and flywheel 26 attached to the crank shaft 23, and this pulley 26. The belt
An electric motor 28 that is rotationally driven via 27 is provided.

Reference numeral 29 is a sliding sleeve as a slide receiving member having a swing fulcrum 30, and the crank arm 25 is slidably inserted in and supported by the sliding sleeve 29. Reference numeral 31 is a support stand fixed on the bed 20.

Reference numeral 32 is a cutter holding device detachably attached to the tip of the crank arm 25.
Two pairs of groove cutters 33 and 34 are supported to form one groove port at the same time. As is clear from the figure, one cutter 33 is attached so as to perform groove cutting when moving forward, and the other cutter 34 is for performing groove cutting when moving backward.

The work holding device 40 is configured as follows. Reference numeral 41 is a spindle that holds the workpiece W fixedly during grooving, 42 is an indexing device that rotates the workpiece W2 by a predetermined angle every time a pair of port grooves is formed, and positions the workpiece W at the next machining position. Is an axial slide unit for separating and contacting the work W with respect to the groove cutters 33, 34.

In the port grooving according to this embodiment, the work W is fixed during grooving, while the cutting blade tips of the groove cutters 33 and 34 have an approximate ellipse having a curve matched with the crank arm tip to the arc shape of the bottom of the port groove. Draw the movement trajectory of the shape, and
This is done by using a cutting depth fine increase means for sequentially increasing the cutting depth for each cycle. In this embodiment, the cutting depth slightly increasing means is a means for changing the radius of curvature of the approximate elliptic curve for each cycle.
In order to gradually increase the crank radius R of the crank device 22 for each cycle, for example, a crank radius varying device such as a facing spindle unit as shown in FIG.
22A is used.

Details of the crank radius changing device 22A are shown in FIG. Reference numeral 22B is a reciprocating shaft having a rack 22C at its tip, and is inserted into a through hole 22E provided in the shaft center portion of a crank shaft 23 that is integrally rotatably connected to a pulley / flywheel 26 via a key 22D. Reference numeral 23a is a housing of the crankshaft 23. 2
2F is a pinion gear that meshes with the rack 22C, 22G is a rack that meshes with this pinion gear 22F, and both racks 22C and 22G are offset by exactly 90 °.

That is, by moving the rack 22C in the axial direction of the crankshaft 23, the rack 22G can be moved in the direction perpendicular to the axial center of the crankshaft 23 via the pinion gear 22F, and the crank integrated with the rack 22G can be moved. Pin 24 to crankshaft 2
It is moved in the direction perpendicular to 3, that is, in the radial direction of the pulley and flywheel 26.

22H is a crankpin support mechanism to which a rack 22G is fixed via bolts 22I and is slidably movable in the arrow (c) direction, that is, in the radial direction. This crank pin support mechanism 22
A crank arm 25 is supported by a crank pin 24 supported by H via a bearing 22J.

22K is a piston integrally connected to the rear end of the reciprocating shaft 22B via a screw 22L, 22M is a piston rod, 22N is the piston 22K and piston rod 22M which are slidably accommodated, and also a pulley and a flywheel. A rotary cylinder attached to the 26 by a bolt 22P so as to be integrally rotatable, 22Q is a fixed cylinder that supports this rotary cylinder 22N through a bearing 22R, and 22S is a piston forward operation air provided on the side surface of this fixed cylinder 22Q. The supply port, 22T, is an air supply port for the backward movement of the piston.

22U is a stroke control mechanism attached to the end of the piston rod 22M, and the dog 2 attached via the arm 22V.
By operating the limit switches 22Y and 22Z with 2W and 22X, the forward limit and the backward limit of the piston 22K and thus the reciprocating shaft 22B are defined.

In FIG. 2, the crankshaft 23 and the crankpin 24 are concentric with each other, and therefore the crank radius R is zero. However, the reciprocating shaft is driven by the piston 22K driven by the supply of air for piston forward movement. When 22B is moved in the direction of arrow (a), the pinion gear 22F moves in the direction of arrow (b), and the rack 2 is moved by moving the pinion gear 22F in the direction of (b).
2G is displaced in the direction of arrow (c), and the crank radius R can be changed by moving the crank pin 24 to which the rack 22G is fixed in the direction (c) perpendicular to the reciprocating shaft 22B. ing.

A workpiece W with no groove is attached to the spindle 41 of the work holding device 40, and the slide unit 43 is used to set the cutters 33 and 34 so as to come to predetermined cutting start positions.

The maximum depth and groove length of the port groove 3 to be cut are determined by the maximum crank radius of the crank device 22, the length of the crank arm 25 and the position of the swing fulcrum 30 of the sliding sleeve 29. By appropriately selecting these, it is possible to match a part of the movement trajectory of the groove cutters 33, 34 with the predetermined arcuate bottom surface shape of the port groove 3. In this case, if the swing fulcrum 30 is fixed to the position closer to the cutter in advance, the swing amount of the groove cutters 33, 34 per rotation of the crank pin 24 will be smaller. Also, crank pin 24 and crank shaft
The distance to 23, that is, the crank radius R is also set small initially by the crank radius varying device 22A. When the crank device 22 rotates once clockwise in FIG. 1, the groove cutters 33, 3
The cutting edge of 4 draws a motion locus having a shape close to an ellipse, as schematically shown by curves 33a to 33b and 34a to 34b in FIG. At this time, the cutter 33 cuts the work inner wall Wa shallowly in an arc shape by the outward curve 33a, and on the return path, follows the arc curve 33b away from the work inner wall Wa and returns to the starting point. On the other hand, the cutter 34 follows the locus of the arc-shaped curve 33a separated from the work inner wall Wa on the outward path, and performs the arc-shaped cutting on the return path curve 34b.

When the above-mentioned 1-cycle approximate elliptic motion is finished, the crank radius variable device 22A is actuated to increase the crank radius R to some extent, and a cycle consisting of the following curves (33c, 33d) and (34c, 34d) is performed. In order to give a cut of about 0.05 mm in one cutting process, crank radius R after each cycle
Is gradually increased. In 40 cycles, about 2mm
A pair of opposing port grooves 3a and 3b having a maximum depth of 3 are formed.

If the work W is a cylindrical sleeve with 6 port grooves, use the indexing device 42 on the spindle 41 that holds the work W.
It is sufficient to give 120-degree index and perform port groove processing similar to the above, and then perform 120-degree index and port groove processing. If the groove cutters 33, 34 are not brought into contact with the inner wall Wa of the work W during this indexing movement, the cutter drive device
You don't have to stop 21 one by one. That is, the crank pin 24 of the crank device 22 is rapidly returned by actuating the crank radius changing device 22A to reduce the crank radius R to the length before the start of the cutter cutting. In this way, the indexing motion can be performed without stopping the continuous operation of the crank device 21, and the machining time can be further reduced, and the machining cost can be significantly reduced, in combination with the method of simultaneously machining two port grooves. It

After all the groove processing is completed, the slide unit 43 retracts to the left to facilitate the attachment / detachment of the work W.

4 and 5 show another embodiment.

In this embodiment, the sliding sleeve 29 is used as a means for slightly increasing the cutting depth.
This is different from the one embodiment in that the swing fulcrum 30 is gradually moved by a swing fulcrum moving device 50A.

That is, in FIG. 4, the support base 50 of the sliding sleeve 29 is
Through a slide table 51 placed on the bed 20, for example, it can be moved in the directions indicated by arrows (f) and (g) by a cylinder actuator 52. The supporting table 50, the sliding table 51, and the cylinder actuator 52 constitute a moving device.

On the other hand, the crank pin 24 in the crank device 22 is fixed, so that the crank radius is constant. When the cut of the port groove 3 is started, the support base 50, that is, the swing fulcrum 30 is moved toward the arrow mark (g) so as to be closer to the cutters 33 and 34 side, and the movement amount of the cutter is reduced. By this, the work inner wall
Wa cutting starts from a very shallow depth of cut. For each cycle, the swing fulcrum 30 is gradually moved in the direction of arrow (f), that is, in the direction away from the cutters 33, 34. As a result, the port groove is gradually and deeply cut (by 0.05 mm, for example). At this time, the locus drawn by the cutting edges of the cutters 33, 34 is shown by a group of approximate elliptic curves whose radius of curvature gradually decreases as it goes deeper, as shown in FIG.

During the indexing operation in this embodiment, the swing fulcrum 30 is
If the cutter 33, 34 and the inner wall Wa of the work are prevented from interfering with each other by moving the cutter 33, 34 rapidly to the position before the start of cutting of the cutter in the arrow (g) direction.

In addition, in both of the above-mentioned embodiments, when the number of the port groove 3 formed in the inner wall Wa of the cylindrical sleeve is one, or when a plurality of port grooves 3 are arranged without facing each other, the forward cutting groove cutter 33 or the backward cutting is used. When only one of the cutting groove cutters 34 is attached to the cutter holding device 32 and used, the cylindrical sleeve 2 having the predetermined port groove 3 is obtained.

〔The invention's effect〕

As described above, according to the present invention, in order to form the predetermined number of port grooves in the cylindrical sleeve, the sleeve held by the indexing device is temporarily fixed, and only the groove cutter has an approximate elliptical motion locus. Since it is configured to oscillate along the edge for cutting, it is possible to perform groove processing with extremely simple processing equipment. Especially for port grooves located at opposite points, a pair of groove cutters are placed at symmetrical positions of the cutter holding device. Since it is possible to cut two grooves each in one cycle by attaching, the number of machining cycles and the number of shaft rotation operations of the indexing device are halved, which significantly shortens the machining time and improves productivity. The effect that a significant cost reduction can be realized is obtained.

[Brief description of drawings]

1, 2 and 3 show an embodiment according to the present invention, and FIG. 1 is a partially cutaway side view of a cylindrical sleeve port groove processing device,
2 is a vertical plan view of a crank radius varying device, FIG. 3 is a schematic diagram for explaining a machining curve of a groove cutter, FIGS. 4 and 5 show other embodiments, and FIG. 4 is a port groove machining device. FIG. 5 is a partial cutaway side view, FIG. 5 is a schematic diagram for explaining a machining curve of a groove cutter, FIG. 6 is a sectional view of a main part of a rotary valve having a cylindrical sleeve, and FIG. 7 is VII-VII of FIG. Sectional view, FIG. 8 is a sectional view showing an example of a conventional cylindrical sleeve port groove, and FIG. 9 is a sectional view showing an example of another conventional sleeve / port groove,
FIG. 10 is a partially enlarged view for explaining the working principle of the sleeve / port groove in FIG. 9, and FIG. 11 is a view showing a motion locus drawn by the working cutter shown in FIG. 2, W …… Cylindrical sleeve Wa …… (sleeve) inner wall 11,33,34 …… Groove cutter 3a, 3b, 3 …… Sleeve / port groove 21 …… Groove cutter drive device 22 …… Crank device 24 …… Crank pin 25 …… Crank arm 29 …… Sliding receiving member 30 …… Swing support 32 …… Cutter holding device R …… Crank radius 40 …… Workpiece holding device 42 …… Indexing device 50A …… Swing support Moving device 22A ... Crank radius variable device

Claims (3)

[Claims] 1. A crank arm slidably inserted in a slide receiving member having a swinging fulcrum is engaged with a crank pin of a crank device and provided at the other end of the crank arm by rotation of the crank pin. A groove cutter driving device that moves the groove cutter holding portion in an approximately elliptical shape, and a cylindrical sleeve processing material that processes the sleeve port groove on the inner side surface are held in correspondence with the groove cutter holding portion, and the groove cutter holding portion is held by the groove cutter holding portion. A cylindrical sleeve port groove machining device comprising: a workpiece holding device that rotates a sleeve machining material at a predetermined angle and retains the sleeve machining material after one step is completed by an approximately elliptical motion of an attached groove cutter. The cylindrical shape provided with a cutting depth fine increasing means for increasing the cutting amount by the movement of the approximate elliptical shape of the groove cutter holding portion to advance the sleeve port groove processing. A Shreveport grooving device,
The groove cutters are attached to both sides of the groove cutter holding portion of the crank arm, and when the crank arm slides forward, one groove cutter is used, and when the crank arm slides back, the other groove cutter is used to face the sleeve material. A cylindrical sleeve port groove processing device, characterized in that sleeve port grooves are formed on both inner surfaces. 2. The cutting depth slightly increasing means increases a turning radius of a crank pin which is provided at a crank device and which is engaged with one end of a crank arm to increase a cutting amount by an approximate elliptical motion of a groove cutter holding portion. The cylindrical sleeve port groove processing device according to claim 1, wherein 3. The groove cutter for moving the position of a slide receiving member having a swinging fulcrum for swinging and slidably supporting the inserted crank arm in the cutting depth slightly increasing means to the crank device side. The cylindrical sleeve port groove machining device according to claim 1, wherein the amount of cutting is increased by an approximately elliptical movement of the holding portion.