KR0125317B1 - Attaching structure for member and attaching strucattaching structure for member & attaching structure for water pump of internal combustion engine ture for water pump of internal combusition engine - Google Patents

Abstract

The present invention aims at simply peeling off the water pump unit 32 housed in the chain chamber so as to be driven by a timing chain, and avoiding the enlargement of the flange portion 44a. The configuration is a chain case rear forming a chain chamber. The pump housing 44 is fitted to the pump attachment part 36 of (4), The opening part for which the operation | work closed by the cover is formed in the front surface of the chain chamber so that the pump housing 44 can enter and exit, and the pump housing ( Although the through hole 57 through which the fixing bolt penetrates is formed in the flange part 44a of 44, the retractor bolt 61 of larger diameter than the fixing bolt is screwed in the inner periphery of this through hole 57. The female thread part 60 is formed, and when the pump unit 32 is removed, after the fixing bolt is removed, the towing bolt 61 is screwed in and the screw housing is gradually inserted so that the pump housing 44 is drawn out. It is.

Description

Member attachment structure and water pump attachment structure of internal combustion engine

1 is a sectional view of principal parts of an internal combustion engine having a water pump according to the present invention;

2 is an exploded perspective view of the front end of an internal combustion engine.

3 is a cross-sectional view of the front end of an internal combustion engine.

4 is a front view showing the configuration within the chain chamber of the internal combustion engine.

5 is a front view showing only the water pump unit.

6 is a cross-sectional view taken along the line B-B of FIG.

7 is an explanatory diagram showing an initial step in disassembling the pump unit.

8 is an explanatory diagram showing an intermediate step in disassembling the pump unit.

9 is an explanatory diagram showing a state in which the pump unit is pushed out by the retractor bolt.

* Description of the symbols for the main parts of the drawings *

1: water pump, 2: cylinder block,

4: chain case rear, 5: chain case front,

6: chain seal, 32: pump unit,

36: pump attachment portion, 44: pump housing,

44a: flange portion, 47: fixing bolt,

51: working opening, 54: through hole,

57: screw hole, 60: female thread portion,

61: Retractor bolt.

The present invention relates to a member attachment structure in which two members fitted together are bolted together and a water pump attachment structure in an internal combustion engine in which a pump unit of a water pump housed in a chain chamber is fixedly coupled to a cylinder block side by bolts.

The water pump of an internal combustion engine is generally comprised by concavely installing a cooling water inlet in front of the cylinder block of an engine, and attaching a pump unit so that it may cover this inlet part. Therefore, this water pump is driven by the crankshaft via the belt transmission mechanism using what is called an auxiliary engine belt. In other words, the pump housing is rotatably supported on the drive shaft via a bearing, and a water pump pulley is attached to one end of which the auxiliary engine belt is wound, and an impeller is attached to the other end of the pump housing between the cylinder block and the pump housing. The impeller rotates in the configuration (see Japanese Utility Model Publication No. HEI1-95529).

Therefore, the pump unit is substantially open to the outside of the engine, so that the pump unit can be relatively easily worked from the outside when the pump unit is replaced due to, for example, a failure of the bearing.

In contrast, in a chain driven internal combustion engine which drives the valve mechanism via a timing chain, it is conceivable to drive the water pump in a timing chain which does not exist in the auxiliary engine (see Japanese Utility Model Laid-Open No. 2-141625). In this case, the water pump unit is arranged in the chain chamber. Further, in the form of the above publication, the main body portion of the water pump unit is disposed outside the chain chamber and only the sprocket portion protrudes in the chain chamber. However, the present applicant fixes the water pump unit to the cylinder block side in the chain chamber and The structure which carried out attachment and detachment through the work opening part provided in the chain case is proposed.

However, if the configuration in which the pump unit is accommodated in such a chain chamber is adopted, the detachment work is very troublesome at the time of inspection or replacement. That is, the pump housing of the water pump generally has a structure fitted to the inner peripheral surface of the pump attachment portion on the cylinder block side, and the flange portion of the pump housing end portion is fixed to the cylinder block side with a plurality of bolts. Therefore, when disassembling the pump unit, it is necessary to pull it out strongly in front of the engine, and work is very bad because this work must be performed in a narrow space.

By the way, the method of using a retractor bolt at the time of withdrawal of such a water pump housing is known. This is a method of forcibly drawing out the pump housing by screwing the retractor bolt into the flange of the pump housing and gradually screwing the tip against the flange face of the cylinder block side, in particular, the place without the screw hole. There is this. In order to employ such a method, it is necessary to form a retractor screw hole for screwing the retractor bolt into the flange portion in advance.

However, in order to use the retractor bolt as described above, a retractor screw hole must be processed in a bolt through hole through which the fixing bolt passes through the flange portion, and the flange portion has a drawback in that size. Therefore, when the size of the flange is restricted, it is undesirable and leads to an unnecessary weight increase.

In particular, in the case of attaching the chain driven water pump, when the flange portion becomes larger, interference with the chain occurs during detachment, or difficulty in securing an opening for inserting only the flange portion becomes difficult, resulting in further workability. It gets worse.

In addition, if the pump unit is arranged in and out of the chain chamber as described in the above publication, it is necessary to disassemble the chain chamber at the time of replacing the pump unit, and the work becomes more cumbersome.

Thus, the present invention has a combination of the screw hole of the retractor bolt and the through hole of the fixing bolt. That is, the member attaching structure of claim 1 has a fitting portion fitted to each other, and a screw hole is formed in the flange member of one member and the screw hole is formed in the other member, respectively, and the fitting insertion of both members is performed. A member attaching structure in which both members are fixedly fixed by bolts parallel to the direction, characterized in that, on the inner circumference of the through hole, a bolt for a retractor having a diameter larger than that of the fixing bolt is formed with a screw thread that can be screwed.

Claim 2 claims that the pump unit is accommodated in a chain chamber formed on the front face of the cylinder block, the pump housing of the pump unit is fitted to the inner periphery of the pump attachment portion in the chain chamber and at the same time insert the bolt into the flange of the pump housing end In the water pump attachment structure of the internal combustion engine in which the through-hole and the screw hole are respectively formed in the cylinder block side, and the pump unit is coupled and fixed by a plurality of bolts parallel to the fitting insertion direction of the pump unit, the front face of the chain chamber A working opening having a size that can be inserted into and detached from the pump unit is provided in the chain casing covering the inner side of the through hole, and a retractor bolt having a diameter larger than the fixing bolt is formed in the inner circumference of the through hole to form a screwable threadable portion. .

In the fixed state, the fixing bolt inserted into the through hole of the flange portion is screwed into the screw hole provided in the other member, for example, a cylinder block, and the like. When removing the fixed member, for example, the pump housing, the fixing bolt is first peeled off, and a retractor bolt having a larger diameter than the fixing bolt is fitted using the female screw portion of the through hole. Then, when the retractor bolt is gradually screwed in, the tip is brought into abutment around the screw hole on the cylinder block side or the like, and conversely, the flange portion is extruded. Thereby, a member, such as a pump housing which is in the fitted state, can be peeled off.

EMBODIMENT OF THE INVENTION Hereinafter, the Example which applied this invention to the attachment structure of the water pump 1 is described in detail based on drawing.

2 is an exploded perspective view showing the configuration of the front end of the V-shaped internal combustion engine including the water pump 1 according to the present invention.

The V-shaped internal combustion engine is, for example, an aluminum die such that the cylinder head 3 is fixed to the upper left and right banks of the cylinder block 2 and covers the front face of the cylinder block 2 and the cylinder head 3, respectively. The chain case rear 4 formed in the plate shape by the cast is attached. The cover-type chain case front 5 is attached to cover the front face of the chain case rear 4, and the chain chamber 6 (see FIGS. 1 and 3) is formed therebetween. . 4 shows a state in which the chain case front 5 is peeled off, that is, the configuration inside the chain chamber 6 in such a V-shaped internal combustion engine. The upper part of the chain chamber 6 is covered by the front end of the cylinder head cover 7 as shown in FIG.

This V-shaped internal combustion engine has a DOHC type copper valve mechanism, and as shown in FIG. 4, a crank sprocket 9 is provided on the crank shaft 8 under the cylinder block 2, and the intake air inside the bank is provided. One timing chain 12 is wound between the first cam sprocket 11 provided on the side camshaft 10 and the crank sprocket 9 so as to form an approximately triangular shape. The first cam sprocket 12 is wound around the intake side camshaft 10. The intake side camshaft 10 is provided with a second cam sprocket 13 having a small diameter overlapping the first cam sprocket 11, and the cam sprocket 15 of the exhaust side camshaft 14 located outside the bank. The sub timing chains 8 are wound around the second cam sprockets 13 adjacent thereto. That is, the intake side camshaft 10 inside the bank is driven by the crankshaft 8 which rotates in the direction of arrow A in FIG. 4, whereby the exhaust side camshaft outside the bank via the sub timing chain 16. As shown in FIG. (14) is configured to work together.

A lower end is rotatably supported between the first cam sprocket 11 and the crank sprocket 9 on the left side of FIG. 4, which is the relaxed side of the timing chain 12, and a hydraulic chain tensioner 17 is provided at the upper end. One chain guide 18 is arranged, whereby an appropriate tension is applied to the timing chain 12. Further, a chain guide 19 is attached between the left and right pairs of first cam sprockets 11, and the timing chain 12 is slightly pressed toward the inner circumferential side.

On the other hand, a water pump 1 is arranged between the first cam sprocket 11 and the crank sprocket 9 on the right side of FIG. 4, which is the tension side of the timing chain 12, and is attached to the drive shaft 20. The water pump sprocket 21 is engaged with the rear side, that is, the outer circumferential side of the timing chain 12. The water pump sprocket 21 is located approximately in the middle of the first cam sprocket 11 and the crank sprocket 9 and is configured to push the timing chain 12 toward the inner circumferential side. Moreover, the chain guides 22 and 23 are arrange | positioned above and below the water pump sprocket 21, respectively.

The side of the chain case rear 4 is partially recessed between the water pump 1 and the exhaust side cam sprocket 15 above, where the thermostat housing 24 is disposed. As shown in FIG. 2 and FIG. 3, the thermostat housing 24 is formed in a cup shape facing forward at the front end of the cylinder head 3, and has an inlet tube containing the thermostat valve 25 therein ( 26) is to be attached.

The water pump 1 includes a pump chamber 31 recessed in the front face of the cylinder block 2 as shown in FIGS. 1 and 3, and a chain case rear 4 corresponding to the pump chamber 31. FIG. It consists roughly of the pump unit 32 attached to it. The pump chamber 31 has a substantially circular shape as shown in FIG. 2, and a discharge port portion 33 extends from the upper portion to the center of the cylinder block 2 along the tangential direction. The discharge port portion 33 communicates with a water jacket (not shown) of the left and right banks. In addition, a coolant passage 34 is formed in the rear of the pump chamber 31 in communication with the inside of the thermostat housing 24, and the coolant passage 34 and the pump chamber 31 have a circular opening ( 35) communicate with each other. In addition, a circular pump attaching portion 36 is formed in the chain case rear 4 positioned at the front surface of the pump chamber 31 in correspondence with the pump chamber 31, and at the peripheral edge thereof, a flat flange surface ( 37) is formed. The chain case rear 4 is fixed to the front face of the cylinder head 3 by a plurality of bolts 38. However, the so-called liquid is used as a sealing agent on the sealing surface between the two, for example, around the pump chamber 31 and the like. The gasket is applied.

The pump unit 32 includes a pump housing 44 attached to the pump attachment portion 36 of the chain case rear 4, a bearing 45 for rotatably supporting the drive shaft 20, and a drive shaft 20. The impeller 46 and the water pump sprocket 21 which are attached to the front-end | tip of the main body are mainly. The pump housing 44 is arranged to be fitted to the inner circumference of the pump attachment portion 36, and three fixing bolts (3) in a state where the flange portion 44a formed at the front end is in close contact with the flange surface 37. 47) is fixed. This fixing bolt 47 is arranged in parallel with the fitting engagement direction of the pump housing 44. In addition, the pump housing 44 and the chain case rear 4 are sealed by a pair of O-rings 53. In addition, a mechanical seal 48 is installed between the pump housing 44 and the impeller 46, and the two are sealed in a rotatable form. In addition, a communication hole 49 is formed in the chain case rear 4 so as to discharge some cooling water or water vapor through the mechanical seal 48 to the outside, and is open to the atmosphere between the cylinder block 2. It communicates with the space 50 (refer FIG. 3).

Moreover, the opening part 51 for a work | work as shown in FIG. 2 is provided in the chain case front 5 corresponding to the attachment position of the pump unit 32 accommodated in the chain chamber 6 as a whole as mentioned above, This is blocked by a separate cover 52. The opening portion 51 has a size that allows the pump unit 32 to be inserted from the front, and the attachment and detachment operation of the pump unit 32 is performed without removing the chain case front 5. In Fig. 2, reference numeral 58 denotes a work opening provided in the chain case front 5 corresponding to the attachment portion of the chain tensioner 17, and 59 denotes a cover for closing the opening 58.

Here, as shown in detail in FIG. 5, the flange portion 44a of the pump housing 44 has an arc-shaped one side portion corresponding to the chain trajectory, and is fixed to three places so as to be outside the chain trajectory. 47) An attachment portion 55 having an insertion hole 54 for expansion is formed on the outer circumferential side. Moreover, in the part which overlaps with a chain trace, the guide surface 56 inclined about 60 degrees to 45 degrees with respect to the front surface 44b of the flange part 44a is formed so that it may follow the rounded end of the water pump sprocket 21 approximately. . Then, as shown in FIG. 7, the screw hole 57 is formed on the flange surface 37 at the peripheral edge of the pump attachment portion 36 of the chain case rear 4 corresponding to the position of the through hole 54. As shown in FIG. The fixing bolt 47 penetrating the through hole 54 is screwed into the screw hole 57 to firmly fix the pump housing 44. In addition, in the two through holes 54 at positions 180 degrees apart from the three through holes 54, a female screw portion 60 is machined in the inner circumference thereof (see Fig. 5). This female thread part 60 is formed with the specification corresponding to the retractor bolt 61 mentioned later which is larger than the fixing bolt 47. As shown in FIG. For example, while the bolt of M6 is used as the fixing bolt 47, the bolt of M8 is used as the bolt for retractor 61, and the female screw part 60 is formed so that this may be screwed together.

Next, the attaching / detaching operation of the water pump unit 32 in the configuration of the above embodiment will be described.

If it is necessary to remove the pump unit 32 by pressing the bearing 45 or the like, first, the covers 52 and 59 of the chain case front 5 are removed and the work openings 51 and 58 are opened. Then, the fixing bolt 47 in the flange portion 44a of the pump unit 32 is removed through the opening 51. At the same time, the chain tensioner 17 is operated through the opening 58 to relax the tension applied to the timing chain 12. As a result, the timing chain 12 can be bent to the inner circumferential side of the chain. Thus, the timing chain 12 is pushed with a finger or the like to be peeled off from the tip of the pump sprocket 21. 7 shows the positional relationship of the timing chain 12 and the like at this time. When the timing chain 12 is removed from this end of the pump sprocket 21, the pump unit 32 is taken out forward.

When pulling out this pump unit 32, as shown in FIG. 9, the retractor bolt 61 is screwed into the female thread part 60 of the through-hole 54, and this screw is gradually inserted. The tip of the retractor bolt 61 abuts against the peripheral edge of the screw hole 57, but cannot be screwed into the screw hole 57, so if the screw is inserted further, as shown in FIG. The pump housing 44 clamped tightly through the ring 53 is forcibly pulled out.

Further, at this time, the timing chain 12 is in the position of FIG. 7 slightly away from this end of the pump sprocket 21, so that when the pump unit 32 is pulled forward, the timing chain 12 is guide surface 56 of the pump housing 44. A). As shown in detail in FIG. 8 with the forward movement of the pump unit 32, the timing chain 12 is moved along the guide surface 56 of the chain inner circumferential side, that is, the flange portion 44a. Guided to the outer circumferential side. Therefore, the timing chain 12 can be peeled off smoothly from the flange part 44a only by pulling the pump unit 32, and the pump unit 32 can be taken out through the opening part 51. FIG. That is, the pump unit 32 can be attached easily, without the troublesome disassembly work of the chain case front 5 etc. with the internal combustion engine in the vehicle loading state.

As apparent from the above description, according to the present invention, since the screw hole for screwing the retractor bolt is also used as a fixing bolt, it is not necessary to form a plurality of holes in the flange portion, thereby increasing the size of the flange portion and Weight gain can be avoided.

In particular, by applying the pump unit housed in the chain chamber, the pump unit can be attached to and detached from the working opening on the front face of the chain chamber, and the workability can be improved. In addition, the detachable work space can be minimized, and the space occupied by the internal combustion engine can be substantially reduced.

Claims (2)

Through-holes for bolt insertion are formed in the flanges of one member and screw holes are formed in the other member, respectively, with the fittings fitted to each other, and both members are fixedly fixed with bolts parallel to the fitting insertion direction of both members. A member attachment structure according to claim 1, wherein a retractor bolt having a diameter larger than that of the fixing bolt is formed on the inner circumference of the through hole so that a female screw portion is screwable. The pump unit is accommodated in a chain chamber formed on the front face of the cylinder block, and the pump housing of the pump unit is fitted to the inner circumference of the pump attachment part in the chain chamber, and a through hole for bolt insertion is provided at the flange of the pump housing end. In the water pump attachment structure of the internal combustion engine in which a screw hole is formed at each block side and the pump unit is coupled and fixed by a plurality of bolts parallel to the fitting insertion direction of the pump unit, the pump is connected to the chain case covering the chain chamber front face. A water pump attachment structure of an internal combustion engine, characterized in that a work opening portion having a size capable of inserting and removing a unit is provided, and a retractor bolt having a diameter larger than the fixing bolt is screwed on the inner circumference of the through hole. .