JP2002235511A - Valve timing control device of internal combustion engine, and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve assembling workability and operation responsiveness by easily and accurately guiding the tip of a cam bolt to a normal screwing position of a camshaft in assembling. SOLUTION: The cam bolt through hole 28 of a vane member 16 is provided with a positioning means for positioning a radial position of the cam bolt 31. The positioning means is constituted with, for example, a guide block 44 comprising a plurality of block pieces 44a divided and formed along the inner peripheral surface of the cam bolt through hole 28. In assembling the vane member 16, the cam bolt 31, while being positioned by the positioning means, can easily and accurately be screwed into the normal screwing position of the camshaft. The guide block 44 is integrally molded simultaneously in molding a die of the vane member 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine (hereinafter referred to as "internal combustion engine").
Say "engine". The present invention relates to a valve timing control device for controlling the opening / closing timing of an intake valve or an exhaust valve according to operating conditions and a method of manufacturing the device.

[0002]

2. Description of the Related Art By rotating a mounting angle between a driving force transmitting member such as a timing pulley or a chain sprocket which rotates synchronously with a crankshaft of an engine and a camshaft having a driving cam on an outer periphery, an intake valve or a valve is driven. BACKGROUND ART A valve timing control device that variably controls the opening / closing timing of an exhaust valve has been conventionally devised, and this technology is disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-186513.

In the valve timing control device described in this publication, a vane member is connected to an end axis of a camshaft by a cam bolt, and the vane member is housed and arranged inside a housing integral with a driving force transmitting member. An advance hydraulic chamber and a retard hydraulic chamber are provided inside the housing, and the vane member is rotated relative to the housing by selectively supplying and discharging hydraulic pressure to each of the hydraulic chambers. The opening / closing timing of the intake valve and the exhaust valve is changed by changing the rotation phase of the transmission member and the camshaft.

Further, in the valve timing control device described in this publication, as shown in FIG. 11, an advance-side supply / discharge passage 1 and a retard-side supply / discharge passage 2 are formed from the camshaft 3 to the vane member 4. One of the supply / discharge passages 1 is formed using a cam bolt insertion hole 5. Specifically, one supply / discharge passage 1 is configured with the following axial holes 6 and radial holes 7 as main parts.

That is, the cam bolt insertion hole 5 is
Is formed larger than the outer diameter of the cam bolt 8 by a predetermined diameter, and an annular gap between the cam bolt insertion hole 5 and the outer peripheral surface of the cam bolt 8 forms an external supply / discharge pipe 9. Are connected to the axial hole 6. A hole is formed in the vane member 4 and extends substantially radially from the center. The hole connects the axial hole 6 to an advance hydraulic chamber or a retard hydraulic chamber (not shown). 7 is set.

Therefore, in this valve timing control device, since a part of one of the supply / discharge passages 1 is formed using the cam bolt insertion hole 5, the number of processing steps can be reduced and the manufacturing cost can be reduced. Also, since it is not necessary to form a passage in the cam bolt 8 itself, sufficient strength of the cam bolt 8 can be secured.

[0007]

Incidentally, in this type of valve timing control device, there has recently been a demand for instantaneously and largely changing the phase of the driving force transmitting member and the camshaft. A large cross-sectional area of the supply / discharge passage must be ensured.

In the case of the conventional valve timing control device described above, if the cross-sectional area of the axial hole 6 is to be increased to satisfy the above requirements, the inner diameter of the cam bolt insertion hole 5 becomes large. The tip end of the bolt 8 is hard to enter the proper screwing position, and the workability in assembling is reduced.

Further, in the above-mentioned conventional apparatus, the outer peripheral surface from the substantially center of the cam bolt 8 in the axial direction to the base side is:
Since the cam bolt 8 is used for the axial hole 6 extending from the vane member 4 to the camshaft 3, the cam bolt 8 inevitably has an increased axial length, and the cam bolt 8 is easily bent during assembly. When the cam bolt 8 is bent, the cross-sectional shape of the axial hole 6 becomes partially asymmetric, and the flow of hydraulic oil flowing from the axial hole 6 to each radial hole 7 varies for each passage hole 7. . As a result, the operation at the time of the valve timing control becomes unstable, and the operation responsiveness is reduced.

In view of the above, the present invention aims at improving the assembling workability and the operation responsiveness by enabling the tip of the cam bolt to be easily and accurately guided to the proper screwing position of the camshaft at the time of assembling. It is an object of the present invention to provide a valve timing control device for an internal combustion engine which can be realized.

[0011]

Means for Solving the Problems As means for solving the above-mentioned problems, the invention described in claim 1 is a driving force transmitting member driven by a crankshaft of an internal combustion engine, and an engine valve on an outer periphery. A camshaft having a driving cam for causing the driving force transmission member to rotate relative to the driving force transmission member as required, and receiving a power from the driving force transmission member to rotate following the driving shaft; and A housing integrated with the member and rotating; a vane member housed in the housing and integrally fixed to the cam shaft by a cam bolt; and a vane member provided in the housing and rotating the vane member by hydraulic pressure. A plurality of pairs of advanced hydraulic chambers and retard hydraulic chambers, and the advanced hydraulic chambers and the retard hydraulic chambers, and selectively supply hydraulic pressure to these hydraulic chambers. A supply / discharge passage of a hydraulic supply / discharge means for supplying / discharging hydraulic oil to / from one side of the advance hydraulic chamber and the retard hydraulic chamber, the vane member and a cam bolt insertion hole of a cam shaft. A valve timing control device for an internal combustion engine, comprising: an axial hole formed by a gap between outer peripheral surfaces of cam bolts; and a radial hole communicating the axial hole with one of an advance hydraulic chamber and a retard hydraulic chamber. In the above, the cam bolt insertion hole of the vane member may be provided with a positioning means for positioning a radial position of the cam bolt.

In the present invention, when assembling the vane member to the cam shaft, the cam bolt is inserted into the cam bolt insertion hole of the vane member and the cam shaft, and the tip end of the cam bolt is screwed into the cam shaft. In this case, the bolt is guided by the positioning means. Therefore, the cam bolt is screwed into the camshaft with the correct posture.

According to a second aspect of the present invention, the positioning means is constituted by a guide block projecting radially inward from the inner surface of the cam bolt insertion hole of the vane member.

In the case of the present invention, the cam bolt can be accurately guided only by projecting the guide block to the vane member.

According to a third aspect of the present invention, the guide block is formed by dividing the guide block into a plurality of block pieces along the inner peripheral surface of the cam bolt insertion hole of the vane member, and the groove between the adjacent block pieces is made of hydraulic oil. Passage.

In the case of the present invention, since the hydraulic oil passes through the groove between the adjacent block pieces, the flow of the hydraulic oil is not affected at all even if the guide block has a sufficiently long axial length.

According to a fourth aspect of the present invention, the groove between the block pieces is formed by a curved surface that tapers toward the radial hole.

In the case of this invention, the hydraulic oil introduced into the groove between the block pieces is supplied to the advance hydraulic chamber or the retard hydraulic chamber through the radial hole. The hydraulic oil flowing toward the radial hole smoothly flows into the radial hole along the curved surface of the groove.

According to a fifth aspect of the present invention, the guide block is formed as an integral undivided block, and is extended to a seat surface with which the head of the cam bolt abuts.

In the case of the present invention, the contact area between the head of the cam bolt and the seat surface is enlarged.

According to a sixth aspect of the present invention, in the method for manufacturing a valve timing control device according to any one of the second to fifth aspects, the vane member is formed by molding, and a guide block is formed at the time of molding the vane member. Was integrally molded.

[0022]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIGS. 1 to 5 show a first embodiment of the present invention. In FIG. 2, reference numeral 11 denotes a cam shaft on the exhaust side of the engine. The camshaft 11 is rotatably supported by a cylinder head 12, and a drive cam 13 for opening and closing an exhaust valve (engine valve) is provided on the outer periphery of a main portion of the camshaft 11.

The valve timing control device according to the present invention includes a chain sprocket 14 as a driving force transmitting member which is rotationally driven by a crankshaft (not shown) via a timing chain (not shown), and this chain. A housing 15 having a sprocket 14 integrally formed on the outer peripheral surface, the camshaft 11 assembled at one end so that the housing 15 can be rotated as necessary, and an integral part at a front end of the camshaft 11. A vane member 16 assembled and rotatably housed inside the housing 15, and a hydraulic pressure supply for rotating the vane member 16 forward and reverse (relative rotation with respect to the housing 15) by hydraulic pressure according to the operating state of the engine. Ejecting means 17
And a lock mechanism 18 that regulates the fluctuation of the vane member 16 due to the reaction force from the exhaust valve.

As shown in FIGS. 1 and 2, the housing 15 has a substantially cylindrical housing main body 19 having four partition walls 23 each having a trapezoidal cross section protruding from the inner peripheral surface at intervals of approximately 90 °.
A front cover 21 disposed on the front end side of the housing main body 19, and a rear cover 22 disposed on the rear end side of the housing main body 19 and having the chain sprocket 14 integrally formed on the outer peripheral surface thereof. The members are connected by a plurality of bolts 20.

On the other hand, the vane member 16 has a substantially cylindrical body 24 and four blades 25 projecting radially from the outer peripheral surface of the body 24. , And each blade 25 is disposed between adjacent partition walls 23 of the housing 15. An advanced hydraulic chamber 26 is provided between the one side surface of each blade portion 25 of the vane member 16 and the partition wall 23 facing the one side surface.
A retard angle hydraulic chamber 27 is provided between the other side surface of each blade portion 25 and the partition wall 23 opposed thereto.

Further, as shown in FIG.
A cam bolt insertion hole 28 is formed at the axial position of the body portion 24, and a concave portion 29 is formed on the rear surface side of the body portion 24 so as to be continuous with the cam bolt insertion hole 28. Vane member 1
6 fits the recess 29 into the front end of the camshaft 11;
The camshaft 11 is connected to the camshaft 11 by a cam bolt 31 in a state where the camshaft 11 is positioned in a rotational direction by a positioning pin 30.

The camshaft 11 is formed in a hollow shape, and is located at a predetermined distance from the tip end thereof.
2 is press-fitted and fixed. The plug 32 is for screwing the tip of the cam bolt 31 to the camshaft 11, and has a threaded hole at the axis thereof.
A tube 33 for forming a passage having a reduced diameter at an intermediate portion is press-fitted into the hollow portion at the tip of the camshaft 11, and an annular passage 34 is formed between the inner peripheral surface of the camshaft 11 and the tube 33. I have. And the cylinder head 12
A pair of annular grooves 3 spaced apart in the axial direction
5 and 36 are provided, and a portion of the camshaft 11 facing these annular grooves 35 and 36 is provided with the tube 33.
A first port 37 communicating with the outer annular passage 34 and a second port 38 communicating with the inner space of the tube 33 are formed.

The vane member 16 at the tip of the camshaft 11
As shown in FIGS. 2 and 4, a passage hole 39 communicating with the annular passage 34 is formed in a portion to be fitted into the concave portion 29. The passage hole 39 is formed in the vane member 16. It communicates with each advance hydraulic chamber 26 via the annular groove 40 and the plurality of radial holes 41.

On the other hand, the inner space of the tube 33 communicates with the cam bolt insertion hole 28 of the vane member 16 via the tip of the cam shaft 11. The inner space of the tube 33 and the inner peripheral surface on the distal end side of the camshaft 11 constitute a cam bolt insertion hole on the camshaft 11 side. The cam bolt insertion hole on the camshaft 11 side and the cam bolt insertion hole 28 on the vane member 16 form an axial hole 42 between the outer peripheral surface of the cam bolt 31 inserted therein. The vane member 16 is formed with a plurality of radial holes 43 extending substantially radially from the cam bolt insertion holes 28 and communicating the insertion holes 28 with the respective retard hydraulic chambers 27.

Here, a guide block 44 as positioning means for positioning the cam bolt 31 in the radial direction when the cam bolt 31 is inserted is provided on the inner surface of the cam bolt insertion hole 28 on the vane member 16 side. As shown in an enlarged manner in FIG. 3, the guide block 44 includes a plurality of block pieces 44 a along the inner peripheral surface of the cam bolt insertion hole 28.
, And the adjacent block pieces 44a, 44
A groove 45 extending in the axial direction is formed between 4a. The distal end of each block piece 44a is formed in an arc slightly larger than the outer diameter of the bolt 31 so that the cam bolt 31 can be inserted.
An opening is provided in a groove 45 between 4a and 44a. The groove 45 between the block pieces 44a, 44a is formed with a curved surface that tapers toward each radial hole 43.

As shown in FIG. 2, the hydraulic supply / discharge means 17 includes a first hydraulic passage 4 for supplying and discharging hydraulic pressure to the advance hydraulic chamber 26.
6 and a second hydraulic passage 4 for supplying and discharging hydraulic pressure to the retard hydraulic chamber 27.
7, a supply passage 48 and a drain passage 49 are connected to the two hydraulic passages 46 and 47 via electromagnetic switching valves 50 for switching the passages. First hydraulic passage 4
Reference numeral 6 denotes an annular groove 35 of the cylinder head 12, a first port 37 of the camshaft 11, an annular passage 34, a passage hole 39, an annular groove 40 and a radial hole 41 of the vane member 16, and the like, and a second hydraulic passage 47. Is constituted by an annular groove 35 of the cylinder head 12, a second port 38 of the camshaft 11, an axial hole 42 in the peripheral area of the cam bolt 31, a radial hole 43 of the vane member 16, and the like. An oil pump 52 for pumping oil in an oil pan 51 is provided in the supply passage 48, and an end of the drain passage 49 communicates with the oil pan 51. The electromagnetic switching valve 50 is controlled by a controller 53, and various signals indicating the operating state of the engine, such as the engine speed, the engine load, and the water temperature, are input to the controller 53.

In the figure, reference numeral 54 denotes a metal target plate attached to the protruding portion of the vane member 16 for detecting the rotational position of the cam shaft 11.

Since the valve timing control device has the above-described configuration, when the engine is started, the vane member 16 is rotated with respect to the housing 15 to the advanced side as shown in FIGS. Locked by the lock mechanism 18, the rotation of the chain sprocket 14 is transmitted to the camshaft 11 in that state. Therefore, at this time, the camshaft 11 opens and closes the exhaust valve at the advanced timing.

After the engine is started in this state, the supply passage 48 is connected to the second hydraulic passage 47 by operating the electromagnetic switching valve 50, and the drain passage 49 is connected to the first hydraulic passage 46.
At this time, the lock mechanism 18 is released at this time, high-pressure hydraulic oil is introduced into the retard hydraulic chamber 27 through the second hydraulic passage 47, and the vane member 16 is
7 rotates to the retard side with respect to the housing 15 under the pressure of 7. As a result, the camshaft 11 opens and closes the exhaust valve at the retard timing.

On the contrary, when the supply passage 48 communicates with the advance hydraulic chamber 26 and the drain passage 49 communicates with the retard hydraulic chamber 27 by operating the electromagnetic switching valve 50 in this state, the vane member 16 The camshaft 11 opens and closes the engine valve at the advanced timing with the rotation of the housing 15 at the advanced timing by receiving the pressure of the chamber 26.

By the way, in the case of this valve timing control device, a plurality of block pieces 44a (guide block 4a) extend along the inner peripheral surface of the cam bolt insertion hole 28 of the vane member 16.
4), the cam bolt 31 is inserted into the cam bolt insertion hole 28 at the time of assembling, and when the tip end is screwed into the camshaft 11 (the screwing plug 32), the cam bolt 31 includes a plurality of block pieces 44a. , And is accurately maintained in a normal posture.

Therefore, the screwing operation of the cam bolt 31 can be easily performed, and the cam bolt 31 is not bent at the time of screwing. Therefore, the axial holes 42 formed in the peripheral region of the cam bolt 31 have an exactly symmetrical shape, and each of the radial holes 4
The flow of the hydraulic oil toward 3 is all uniform. As a result, the operation responsiveness at the time of changing the valve timing is improved.

In the valve timing control device of this embodiment, the guide block 44 is formed by a plurality of block pieces 44a.
Since the groove 45 for allowing the flow of the hydraulic oil is formed between the a and 44a, the axial width of the guide block 44 is sufficiently widened, and the guide of the cam bolt 31 by the guide block 44 is further stabilized. Can be.

Further, in the case of this embodiment, since the groove 45 formed between the adjacent block pieces 44a, 44a is formed by a curved surface tapering toward the radial hole 43, the groove 45 is formed from the axial hole 42. The hydraulic oil flowing toward each radial hole 43 smoothly flows along the curved surface. Therefore, there is an advantage that the operation responsiveness can be further improved.

In this embodiment, the vane member 16
Includes the block piece 44a forming the guide block 44,
The whole is simultaneously and integrally formed by die molding such as sintering or aluminum die casting. Therefore, according to this manufacturing method, there is an advantage that the guide block 44 can be provided on the vane member 16 with little increase in manufacturing cost by only slightly changing the shape of the mold.

Next, a second embodiment of the present invention shown in FIGS. 6 and 7 will be described.

The overall configuration of the valve timing control device of this embodiment is the same as that of the first embodiment described above, except that the shape of the guide block 144 formed in the cam bolt insertion hole 28 of the vane member 16 and its shape The formation range is different from that of the first embodiment.

That is, the guide block 14 of this embodiment
4 is not formed divided in the circumferential direction, but is integrally formed so as to uniformly project radially inward from the inner peripheral surface of the cam bolt insertion hole 28. The guide block 144 is not formed from the concave portion 29 where the front end portion of the camshaft 11 is fitted to the position intersecting the radial hole 43, and the guide block 144 is more than the position intersecting the radial hole 43. It is formed only in the region on the front end side. Also,
In this embodiment, the guide block 144 extends to the seat surface 60 of the vane member 16 with which the head 31a of the cam bolt 31 contacts.

In the case of this embodiment, the guide block 14
4 has a shorter shaft length than that of the first embodiment, but when inserting and screwing in the cam bolt 31, the posture of the cam bolt 31 can be corrected, and assembling workability can be improved. The flow of the hydraulic oil can be stabilized by preventing the cam bolt 31 from bending.

Further, the guide block 14 of this embodiment
4 is a seat surface 60 with which the head 31a of the cam bolt 31 contacts.
The contact pressure between the head 31a of the cam bolt 31 and the seat surface 60 when the cam bolt 31 is tightened,
The deformation of the seat surface 60 and the head 31a can be prevented.
Furthermore, in addition to this, the head 31a of the cam bolt 31
There is an advantage that the contact area of the seat and the seat surface 60, that is, the seal width for preventing the leakage of hydraulic oil can be increased.

FIGS. 8 to 10 show a third embodiment of the present invention. Although the overall configuration of the valve timing control device of this embodiment is also the same as that of the first and second embodiments, the position of the cam bolt insertion hole 28 that intersects with the radial direction hole 43 from the concave portion 29. Up to the guide block 44 divided into a plurality of block pieces 44a.
Are formed, and an integrated guide block 144 is formed on the front end side of the position intersecting with the radial hole 43.

Therefore, in the case of this embodiment, the head 31a of the cam bolt 31 and the seat surface 6 are similar to the second embodiment.
0 can be reduced, the seal width can be increased, and the first
The guide block 44 can be formed over substantially the entire axial width of the vane member 16 as in the embodiment. Therefore, compared to the second embodiment, the cam bolt 31 can be guided with a sufficiently long axial width, and the cam bolt 31 can be maintained in a more accurate posture during assembly.

In the above, an example has been described in which a guide block is formed integrally with the cam bolt insertion hole as positioning means for positioning the cam bolt in the radial direction. However, the positioning means is such that a separate positioning component is attached to the cam bolt insertion hole. You may do it.

[0050]

As described above, the invention according to claim 1 is
Since the cam bolt can be easily and accurately screwed into the regular position of the camshaft while being positioned by the positioning means at the time of assembling the vane member, the assembling workability can be greatly improved, and the cam bolt can be bent. Thus, it is possible to eliminate the variation in the flow of the hydraulic oil due to the above-mentioned factors and to enhance the operation responsiveness.

According to the second aspect of the present invention, since the cam bolt can be accurately guided only by projecting the guide block to the vane member, the assembling workability and the operational response can be improved. High production costs can be suppressed.

According to the third aspect of the present invention, the guide block can have a sufficiently long shaft length without impeding the flow of the hydraulic oil at all, so that the vane member having a small axial dimension can be used. The positioning effect can be sufficiently exhibited.

According to the fourth aspect of the present invention, since the groove between the block pieces is formed by a curved surface that tapers toward the radial hole, the flow of the hydraulic oil from the groove toward the radial hole is smoothed. Operation responsiveness can be further improved.

According to the fifth aspect of the present invention, since the contact area between the head of the cam bolt and the seat surface of the vane member is enlarged, the contact surface pressure of the head when the cam bolt is tightened is reduced to reduce the contact area. Deformation and the like can be prevented, and a sufficient seal width can be ensured between the head of the bolt and the vane member to improve the sealability.

According to the sixth aspect of the present invention, since the guide block is integrally formed at the same time as the molding of the vane member, the guide block can be easily and inexpensively formed in the axial hole of the vane member. Can be.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along line AA of FIG. 2 showing a first embodiment of the present invention.

FIG. 2 is an exemplary cross-sectional view of the same embodiment taken along line DD of FIG. 5;

FIG. 3 is an enlarged sectional view of a portion C in FIG. 1 showing the same embodiment.

FIG. 4 is an exemplary sectional view of the same embodiment taken along line BB of FIG. 2;

FIG. 5 is a view taken in the direction of an arrow E in FIG. 2 showing the same embodiment.

FIG. 6 is a sectional view taken along the line GG of FIG. 7 showing the second embodiment of the present invention.

FIG. 7 is an exemplary sectional view of the same embodiment taken along line FF of FIG. 6;

FIG. 8 is a JJ diagram illustrating a third embodiment of the present invention;
Sectional view along the line.

FIG. 9 is a sectional view of the same embodiment, taken along line HH of FIG. 8;

FIG. 10 is a sectional view of the same embodiment, taken along the line II of FIG. 8;

FIG. 11 is a longitudinal sectional view showing a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Cam shaft 14 ... Chain sprocket 15 ... Housing 16 ... Vane member 17 ... Hydraulic supply / discharge means 26 ... Advance hydraulic chamber 27 ... Retard hydraulic chamber 28 ... Cam bolt insertion hole 31 ... Cam bolt 42 ... Axial hole 43 ... Radial direction Holes 44, 144: guide block 44a: block piece 45: groove

Continued on the front page F term (reference) 3G018 AB02 AB16 BA33 CA20 DA73 DA75 DA84 DA85 DA86 EA02 EA11 EA17 FA01 FA07 GA02 GA03 GA17

Claims (6)

[Claims] 1. A driving force transmitting member driven by a crankshaft of an internal combustion engine, and a driving cam for operating an engine valve on an outer periphery, wherein the driving force transmitting member can be relatively rotated as required. A camshaft that is driven and rotated by receiving power from the driving force transmission member; a housing that rotates integrally with the driving force transmission member; and a housing that is housed in the housing and that is mounted on the camshaft. A vane member integrally fixed by a cam bolt; a plurality of pairs of advance hydraulic chambers and retard hydraulic chambers provided in the housing and rotating the vane members by hydraulic pressure; and the advance hydraulic chambers and the retard hydraulic pressure And a hydraulic supply / discharge means for selectively supplying and discharging hydraulic pressure to and from these hydraulic chambers, and supplying hydraulic oil to one of the advance hydraulic chamber and the retard hydraulic chamber. The supply / discharge passage of the hydraulic supply / discharge means for discharging includes an axial hole formed by a gap between the vane member and the cam bolt insertion hole of the camshaft and the outer peripheral surface of the cam bolt, and the axial hole is connected to the advance hydraulic chamber and In a valve timing control device for an internal combustion engine having a radial hole communicating with one side of a square hydraulic chamber, a positioning means for positioning a radial position of a cam bolt is provided in a cam bolt insertion hole of the vane member. A valve timing control device for an internal combustion engine. 2. The valve timing control device for an internal combustion engine according to claim 1, wherein said positioning means is constituted by a guide block projecting radially inward from an inner surface of the cam bolt insertion hole of the vane member. 3. The guide block is formed by dividing the guide block into a plurality of block pieces along an inner peripheral surface of the cam bolt insertion hole,
3. The valve timing control device for an internal combustion engine according to claim 2, wherein a groove between adjacent block pieces is a passage for hydraulic oil. 4. The valve timing control apparatus for an internal combustion engine according to claim 3, wherein the groove between the block pieces is formed by a curved surface that tapers toward a radial hole. 5. The valve timing control apparatus for an internal combustion engine according to claim 2, wherein the guide block is an integral block that is not divided, and the guide block extends to a seat surface with which the head of the cam bolt abuts. 6. The method of manufacturing a valve timing control device according to claim 2, wherein the vane member is formed by molding, and the guide block is integrally molded when the vane member is molded. A method for manufacturing a valve timing control device, comprising: