WO2007083386A1

WO2007083386A1 - Decompression device for internal combustion engine

Info

Publication number: WO2007083386A1
Application number: PCT/JP2006/300836
Authority: WO
Inventors: Ryo Kubota; Masahide Mimura
Original assignee: Honda Motor Co., Ltd.
Priority date: 2006-01-20
Filing date: 2006-01-20
Publication date: 2007-07-26
Also published as: BRPI0605894B1; MY141470A; JPWO2007083386A1; TW200745443A; JP4260841B2; BRPI0605894A2; TWI325920B; AR058993A1

Abstract

A decompression device for an internal combustion engine, where a decompression cam is attached to one side of a cam shaft and a stopper piece is attached to a cam shaft holder for supporting the cam shaft in cooperation with a cylinder head. The decompression cam incorporates a one-way clutch that can transmit torque only when a cam shaft is rotated in the reverse direction. The stopper section stops operation of the decompression cam when the cam shaft is rotated in the normal direction.

Description

Specification

Decompression device for internal combustion engine

Technical field

TECHNICAL FIELD [0001] The present invention relates to a deconvolution apparatus for an internal combustion engine for a vehicle such as a motorcycle.

Background art

Conventionally, a cylinder part is disposed with its axis substantially horizontal, and a cylinder head having an intake port and an exhaust port in the cylinder part is supported by a camshaft that opens and closes an intake / exhaust valve. In the crushing device, a deconvolution mechanism having a built-in one-way clutch capable of transmitting torque only when the camshaft is reversely rotated is attached to one side of the camshaft, and when the camshaft is rotating forward, A stopper mechanism for stopping the operation of the compression mechanism may be attached to the cylinder head (for example, see Patent Document 1).

Patent Document 1: JP 2002-295721 A

Disclosure of the invention

Problems to be solved by the invention

[0003] By the way, in the above conventional configuration, the stopper mechanism is directly attached to the cylinder head, and it is difficult to attach the stopper mechanism to the cylinder head and to assemble the camshaft and the decompression mechanism. Also, by providing the cylinder head with the stopper mounting part, the weight of the cylinder head was increased and the structure was easy to complicate. Also, with the conventional configuration, it was difficult to machine the stopper mounting part of the cylinder head.

The present invention has been made in view of the above circumstances, and in a deconvolution apparatus for an internal combustion engine, it is easy to assemble the engine, reduce the weight of the cylinder head, simplify the structure, and manufacture the cylinder head. The purpose is to make it easier.

Means for solving the problem

[0004] As a means for solving the above-described problems, the deconvolution apparatus of the present invention includes a cylinder head (for example, an intake port 49 and an exhaust port 50 in the embodiment) (for example, an intake port 49 and an exhaust port 50). For example, the cylinder head 24) of the embodiment, the intake / exhaust valves for opening and closing the intake / exhaust port (for example, the intake valve 51 and the exhaust valve 52 of the embodiment), and the intake / exhaust valve supported by the cylinder head on its own rotation. An internal combustion engine (for example, the embodiment), and a camshaft holder (for example, the camshaft holder 65 of the embodiment) that supports the camshaft together with the cylinder head. The deconvolution device of the engine 20), which is attached to the camshaft and transmits a torque only when the camshaft is reversely rotated (for example, implemented) Decompression mechanism with built-in one-way clutch 66) (for example, decompression cam 67 in the embodiment); Stopper mechanism for the stopping the operation of the de-kelp column Chillon mechanism during normal rotation of the installed pre-Symbol camshaft Yafutohoruda and (stopper piece 72 of the Examples);! Includes a /, and wherein Rukoto.

[0005] The decomvolution apparatus of the present invention is characterized in that a stopper mounting portion (for example, the stopper mounting portion 73 in the embodiment) force for mounting the stopper mechanism is integrally formed with the camshaft holder. And

[0006] The deconvolution apparatus of the present invention is characterized in that the camshaft holder force and the cylinder head have a separate structure. The invention's effect

[0007] According to the present invention, a stopper mechanism can be assembled in advance in the camshaft holder, and the number of engine assembly steps can be reduced. Further, since the stopper mounting portion is eliminated from the cylinder head having a relatively complicated structure, the weight of the cylinder head can be reduced, the structure can be simplified, and the cylinder head can be easily manufactured. In addition, the cylinder head and stopper mechanism are separate structures, making it possible to eliminate the need to prevent damage to the stopper mechanism during engine assembly.

[0008] According to the present invention, the number of parts around the cylinder head can be reduced to reduce the cost.

According to the present invention, before the camshaft holder is attached to the cylinder head, the hole for attaching the stopper mechanism to the force shaft holder can be easily processed, and the stopper mechanism itself can be attached easily. Brief Description of Drawings

FIG. 1 is a left side view of a motorcycle according to an embodiment of the present invention.

FIG. 2 is a right side view of the motorcycle engine.

FIG. 3 is a developed sectional view of the engine.

FIG. 4 is a right cross-sectional explanatory view of the cylinder head of the engine.

FIG. 5 is an enlarged cross-sectional view of the periphery of the engine deconvolution apparatus. 6] It is a first operation explanatory view of the decomvolution apparatus.

[7] A second operation explanatory view of the decomvolution apparatus.

[8] FIG. 8 is a third action explanatory view of the decomvolution apparatus.

[9] FIG. 9 is a fourth action explanatory diagram of the decomvolution apparatus.

FIG. 10 is a cross-sectional view taken along the line AA in FIG.

FIG. 11 is a cross-sectional view taken along the line BB in FIG.

Explanation of symbols

1 Motorcycle (vehicle)

20 engine (internal combustion engine)

22 Cylinder part

24 Cylinder head

49 Inlet port

50 Exhaust port

51 Intake valve

52 Exhaust valve

57 Camshaft

65 Camshaft Honoreda

66 One-way clutch (one-way clutch)

67 Decompression cam (compression mechanism)

72 Stopper piece (Stopper mechanism)

73 Stopper attachment

C axis BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the directions such as front, rear, left and right in the following description are the same as those in the vehicle unless otherwise specified. In the figure, arrow FR indicates the front of the vehicle, arrow LH indicates the left side of the vehicle, and arrow UP indicates the upper side of the vehicle.

In the motorcycle (vehicle) 1 shown in FIG. 1, left and right front forks 5 that pivotally support the front wheels 4 are connected via a steering stem 6 to the head pipe 3 positioned at the front end of the body frame 2. It is pivotally supported. A steering bar handle 7 is attached to the top of the steering stem 6.

[0014] The body frame 2 extends a single main tube 8 obliquely downward and rearward from the head pipe 3, and improves the ease of straddling with a lower portion between the head pipe 3 and the occupant seat 9. It is a so-called backbone type. The left and right pivot plates 10 are connected to the rear end portion of the main tube 8, and the front end portion of the swing arm 12 that pivotally supports the rear wheel 11 is pivotally supported on the left and right pivot plates 10.

[0015] The front end portions of the left and right seat frames 13 extending obliquely upward and rearward are joined to the rear portion of the main tube 8, and the front and rear intermediate portions of the left and right seat frames 13 and the left and right arm rear end portions of the swing arm 12 are connected. The left and right rear cushions 14 are respectively disposed between the two. Above the left and right seat frames 13, the seat 9 having seat surfaces for the driver and the rear passenger on the front and rear is arranged. In the figure, reference numeral 15 denotes a driver step, and reference numeral 16 denotes a rear passenger step.

[0016] An engine (internal combustion engine) 20 that is a prime mover of the motorcycle 1 is disposed inside the center lower part of the body frame 2 (inside the lower part). The engine 20 is an air-cooled four-stroke single-cylinder engine whose crank rotation axis is aligned in the vehicle width direction (left-right direction). The cylinder part 22 is substantially horizontal from the front end of the crankcase 21 toward the front of the vehicle. Has a basic structure. The engine 20 is supported by the left and right pivot plates 10 at the rear upper and lower parts of the crankcase 21, and the upper part of the crankcase 21 is supported by the front and rear intermediate portions of the main tube 8 via the engine hanger 8a. Installed in 2.

[0017] The cylinder head 24 on the front end side (front end side) of the cylinder portion 22 is connected to the throttle port from above. The downstream side of D 26 is connected, and the bottom end side of exhaust pipe 27 is connected to the lower side thereof. Connected to the upstream side of the throttle body 26 is an air turner case 26a supported on the lower front side of the main tube 8. The exhaust pipe 27 is bent appropriately below the cylinder head 24 and then extends rearward, and is connected to a silencer 27a located behind the engine 20. A catalytic converter 28 for exhaust gas purification is provided diagonally below and to the left of the cylinder portion 22 in the exhaust pipe 27.

Rotational power from the engine 20 is output to a drive sprocket 32 on the left side of the rear of the crankcase 21 via a clutch and a transmission housed in the crankcase 21, and the drive sprocket 32 passes through the drive chain 33 from the drive sprocket 32. Is transmitted to the dribbling socket 34 on the left side of the rear wheel 11.

[0019] The front part of the body frame 2, the cylinder part 22 of the engine 20, the throttle body 26, the air cleaner case 26a and the like are covered with a front body cover 35 made of synthetic resin. The front vehicle strength bar 35 also serves as a redder shield that protects the driver's legs against wind force and other forces. The rear portion of the vehicle body frame 2 is covered with a rear vehicle body cover 36 that is also made of synthetic resin. The rear body cover 36 supports the seat 9 together with the left and right seat frames 13. An article storage box 37 located under the seat 9 is disposed in the rear part of the vehicle body frame 2, and a fuel tank supported by the front part of the left and right seat frames 13 below the front part of the article storage box 37. 38 is arranged.

[0020] As shown in FIG. 2, the cylinder portion 22 of the engine 20 has its axis C substantially horizontal (in detail, slightly lifted forward) with respect to the ground, and the crankcase 21 front end force is also forward (vehicle traveling direction). The cylinder body 23 attached to the front end of the crankcase 21, the cylinder head 24 attached to the front end of the cylinder body 23, and the head cover 25 attached to the front end of the cylinder head 24, It has. Hereinafter, the front-rear direction parallel to the axis C (cylinder axis) in the cylinder portion 22 may be referred to as the cylinder front-rear direction, and the vertical direction perpendicular to the axis may be referred to as the cylinder vertical direction. The cylinder head 24, the cylinder body 23, and a camshaft holder 65, which will be described later, are integrally coupled to the crankcase 21 by a plurality of bolts that penetrate these from the front of the vehicle (see FIG. 4). In addition, the head cover 25 is configured such that the camshaft holder 65 and the sili Fixed to the solder head 24.

Referring also to FIG. 3, the cylinder body 23 has a cylinder bore 39 along the axis C formed therein, and a piston 40 is fitted in the cylinder bore 39 so as to be able to reciprocate. A small end portion of a connecting rod 41 is connected to the piston 40 via a piston pin extending in the left-right direction, and the large end portion of the connecting rod 41 is connected to the crankshaft 42 via a crank pin extending in the left-right direction. It is connected rotatably. Crankshaft 42 is the normal luck of engine 20

As the piston 40 reciprocates, it rotates clockwise in FIG.

A centrifugal clutch 29 is coaxially arranged at the right end portion of the crankshaft 42, and the rotational power of the crankshaft 42 is transmitted to the primary drive gear 43 through the centrifugal clutch 29 according to the rotational speed. The primary drive gear 43 is coaxially disposed on the right shaft portion of the crankshaft 42 (on the right side when the crank portion force is viewed), and the primary drive gear 43 is located on the right side of the main shaft 45 behind the crankshaft 42, and the main shaft 45 It meshes with the primary driven gear 44 that is coaxially arranged on the shaft. The main shaft 45 is arranged behind the crankshaft 42 and in parallel with the left and right shaft portions of the crankshaft 42, and a multi-plate clutch 30 capable of intermittently transmitting power by a driver's operation is provided at the right end portion of the main shaft 45. The rotational power input to the primary driven gear 44 is transmitted to the main shaft 45 through the multi-plate clutch 30.

[0023] The main shaft 45 supports a transmission gear group 47 (only one pair of transmission gears fitted to each other is shown in Fig. 3) 47 together with a counter shaft 46 arranged in parallel behind the main shaft 45. Constitutes the basic structure of the transmission 31, and the reduction ratio of the transmission gear group 47 is changed in multiple stages through a change mechanism (not shown) by the operation of the driver. The left end portion of the counter shaft 46 projects out of the crankcase 21 and the drive sprocket 32 is attached to the left end portion. 2 denotes a starter motor that starts the engine 20.

Referring also to FIG. 5, the cylinder head 24 closes the front end opening of the cylinder bore 39 and forms a so-called pent roof type combustion chamber together with the piston 40 at the top dead center. The engine 20 in this embodiment is an OHC two-valve, and the combustion chamber side openings of the intake port 49 and the exhaust port 50 are respectively formed on two inclined upper surfaces in the roof forming portion of the combustion chamber. Each combustion chamber side opening is an intake valve 51 and an exhaust valve 5 respectively. Opened and closed by 2.

[0025] Each port 49, 50 is a flow passage that communicates the combustion chamber with the throttle body mounting portion 53 at the top of the cylinder head 24 or the exhaust pipe mounting portion 54 at the bottom of the cylinder head 24. After extending obliquely forward so as to be substantially orthogonal to the inclined upper surface, it curves upward or downward to reach the throttle body attachment portion 53 or the exhaust pipe attachment portion 54. The throttle body attaching portion 53 and the exhaust pipe attaching portion 54 form a plane that is substantially perpendicular to the cylinder vertical direction, and the insulator of the throttle body 26 or the coupling flange of the exhaust pipe 27 abuts on each of these planes and is fastened. The

[0026] The stem of each valve 51, 52 extends obliquely forward in a V-shape in a side view so as to be substantially orthogonal to the inclined upper surface, and after passing through the inner wall of the intake / exhaust ports 49, 50, Retainers 52a (shown only on the exhaust valve 52 side in FIG. 5) are fitted and attached to the respective leading ends, and corresponding valve springs 52b (shown only on the exhaust valve 52 side in FIG. 5) are fitted via the retainers 52a. When the panel force is input to the valves 51 and 52, they are urged to close the combustion chamber side openings of the ports 49 and 50.

A single cam shaft 57 that is parallel to the crankshaft 42 is disposed between the stems of each of the knobs 51 and 52. The camshaft 57 is integrally provided with an intake cam 57a and an exhaust cam 57b at an intermediate portion in the longitudinal direction, and both ends are rotatably supported by the cylinder head 24 and the force shaft holder 65 via bearings. A driven sprocket 58 is coaxially fixed to the left end portion of the camshaft 57, and an endless cam chain 60 is wound around the driven sprocket 58 and a drive sprocket 59 coaxially fixed to the left end portion of the crankshaft 42. As a result, the camshaft 57 rotates in the same direction in conjunction with the crankshaft 42.

An intake side or exhaust side rocker shaft 61, 62 that is parallel to the camshaft 57 is disposed between the camshaft 57 and the stem tip portions of the knobs 51, 52, respectively. Each rocker shaft 61, 62 is supported by a camshaft holder 65, and each rocker shaft 61, 62 can swing the intermediate part of the intake side or exhaust side rocker arm 55, 56, respectively. Supported by Cam rollers 56a (see FIG. 5) contact the outer peripheral surfaces of the intake cam 57a or the exhaust cam 57b, respectively, at the end portions of the rocker arms 55, 56 on the cam shaft 57 side. (Only shown on the exhaust valve 52 side) is rotatably supported. On the other hand, tappet bolts 56b (shown only on the exhaust valve 52 side in FIG. 5) are screwed to the other ends of the rocker arms 55 and 56, respectively, and are fixed integrally with a lock nut.

[0029] Each rocker arm 55, 56 is engaged with the stem tip of each valve 51, 52 via the tappet bolt 56b, and when the camshaft 57 rotates, the outer periphery of each cam 57a, 57b. It swings appropriately according to the pattern. Accordingly, the corresponding valves 51 and 52 reciprocate along the system to open and close the combustion chamber side openings of the ports 49 and 50. The stem of each valve 51, 52, each rocker arm 55, 56, camshaft 57, etc. are supported inside the front part of the cylinder head 24, and these are the forces that block the front part of the cylinder head 24 and this. Is housed in a valve operating chamber formed by a head cover 25 in the form of a ring.

Here, a decompression cam (decompression mechanism) 67 provided with a one-way clutch (one-way clutch) 66 is fitted and attached to the right end portion of the camshaft 57. In FIG. 5, when the camshaft 57 rotates clockwise (forward rotation, rotation in the direction of arrow N, where N is the direction of rotation of the camshaft 57 in the normal operation state of the engine 20), When the cam 66 rotates almost counterclockwise in FIG. 5 (reverse rotation in the direction indicated by the arrow R), the reverse rotation torque of the cam shaft 57 is hardly transmitted. Is transmitted. The decompression cam 67 is disposed adjacent to the outside (right side) of the cam roller support portion of the exhaust side rocker arm 56 (see FIG. 3). On the outside of the cam roller support portion of the exhaust side rocker arm 56, a cam contact portion 68 that can contact the outer peripheral surface of the decompression cam 67 is formed.

[0031] On the outer peripheral portion of the deconvolution cam 67 that has a substantially circular shape when viewed from the side, a portion thereof is cut out in a flat shape, and a cutout portion 69 is formed. A cam crest 70 is formed adjacent to the forward direction leading side, and a locking projection 71 is formed farther away from the notch 69 toward the forward direction trailing side. The cam crest 70 is formed on the outer peripheral portion of the decompression cam 67 at a substantially constant height over a predetermined range, and in the state where it is in contact with the cam contact portion 68 of the exhaust side rocker arm 56, the exhaust side rocker arm 56 Is rocked by a predetermined amount. Further, the locking projection 71 is formed on a stopper piece (stopper mechanism) 72 described later in a state where the notch 69 is in contact with the cam contact portion 68 of the exhaust side rocker arm 56. It can be engaged.

[0032] Referring to FIG. 4, FIG. 10, and FIG. 11 in addition to FIG. 5, the portion of the camshaft holder 65 located above the deconvolution cam 67 is disposed along the vertical direction of the cylinder. A stopper mounting portion 73 for forming a through hole is provided, and the stopper piece 72 protruding toward the deconvolution cam 67 is inserted into the stopper mounting portion 73 so as to be capable of reciprocating. A coil spring 74 is loosely fitted in the stopper attaching portion 73, and a sealing bolt 75 is screwed onto the coil spring 74 to generate a panel force on the coil spring 74, and the stopper piece 72 is released by the spring force. It protrudes downward to engage with the locking projection 71 in a state of being urged toward the convergence cam 67 side.

[0033] That is, when the decompression cam 67 rotates forward with the stopper piece 72 protruding (clockwise in FIG. 5), the locking projection 71 engages with the stopper piece 72, and the decompression cam 67 Stop normal rotation of 67. In addition, an inclined surface 71a is formed on the downstream side of the locking projection 71 in the forward rotation direction, and when the deconvolution cam 67 reverses (counterclockwise in FIG. 5), the locking projection 71 The stopper piece 72 rides on the inclined surface 71a of the part 71, piles on the panel force of the coil spring 74 and is pushed into the stopper mounting part 73, and the locking projection 71 moves over the stopper piece 72 and the decomposing cam. Allows 67 reverses.

Next, the operation of the deconvolution device for the engine 20 will be described.

First, when the normal operation state force of the engine 20 is also stopped, the rotation of the crankshaft 42 stops before the top dead center of the compression stroke due to the pressure increase in the combustion chamber. FIG. 5 shows the positions of the intake cam 57a and exhaust cam 57b of the camshaft 57 and the decompression cam 67 at this time.

[0035] After the crankshaft 42 is stopped as shown in FIG. 5, the piston 40 is pushed down by the pressure in the combustion chamber, and the crankshaft 42 is slightly reversed and stationary. At this time, as shown in FIG. 6, the camshaft 57 and the deconvolution cam 67 are both reversed and stationary by the half of the rotation angle of the crankshaft 42 by the action of the one-way clutch 66. As a result, the cam contact portion 68 of the exhaust side rocker arm 56 rides on the cam crest portion 70 of the deconvolution cam 67, and the exhaust side rocker arm 56 swings to operate the exhaust valve 52, while being in the compression stroke. The combustion chamber side opening of the exhaust port 50 opens. When the camshaft 57 rotates in the forward direction in conjunction with the crankshaft 42 that is rotated by the starter motor 63 or the kick starter from the operation stop state shown in FIG. 6, as shown in FIG. 7, the exhaust cam The force by which 57b approaches the cam roller 56a of the exhaust side rocker arm 56. During this time, the cam contact portion 68 of the exhaust side rocker arm 56 contacts the cam peak portion 70 of the decompression cam 67, so that the decompression Since the cam 67 is applied with a force to stop its rotation, the decompression cam 67 remains stationary regardless of the forward rotation of the camshaft 57.

[0037] When the camshaft 57 further rotates forward from the state shown in FIG. 7 and the cam roller 56a of the exhaust side rocker arm 56 rides on the exhaust cam 57b as shown in FIG. After being separated, the decompression cam 67 becomes completely unrestrained, and after being driven together with the camshaft 57 in the forward direction by the slight forward torque of the one-way clutch 66, the locking protrusion 71 is the stopper piece 72. The rotation of the decomvolution cam 67 stops at that position.

[0038] After the camshaft 57 further rotates forward from the state shown in FIG. 8 and the exhaust cam 57b passes the cam roller 56a of the exhaust-side rocker arm 56 as shown in FIG. The camshaft 67 is in contact with the notch 69 of the cam 67, that is, the same state as that shown in FIG. 5, and the decompression function by the camshaft 67 is automatically released, and the engine 20 is in a normal operation state. Transition smoothly.

As described above, the crankshaft 42 rotates twice while the camshaft 57 rotates, and the piston 40 makes two reciprocations in the cylinder bore 39 to perform four strokes. At this time, the combustion chamber communicates with the atmosphere until the intake stroke is completed via the expansion stroke and the exhaust stroke in the state near the top dead center of the compression stroke shown in FIG. Since the forward-rotation suppressing force of the engine 20 due to the pressure increase is eliminated, the forward rotation of the crankshaft 42 is smoothly and sufficiently accelerated, and the engine 20 can be started reliably.

[0040] As described above, in the deconvolution apparatus in the above-described embodiment, the cylinder portion 22 is arranged with its axis C substantially horizontal, and the cylinder portion 22 has the intake port 49 and the exhaust port 50. Force to open / close intake / exhaust valves 51, 52 to head 24 A decompression cam 67 that is applied to the engine 20 on which the shaft 57 is supported and includes a one-way clutch 66 that can transmit torque only when the camshaft 57 is reversely rotated is a part of the camshaft 57. A stopper piece 72 is attached to a camshaft holder 65 that supports the camshaft 57 together with the cylinder head 24. The stopper piece 72 stops the operation of the deconvolution cam 67 during forward rotation of the camshaft 57. Chino.

[0041] According to this configuration, the stopper piece 72 can be assembled in advance in the camshaft holder 65, and the number of engine assembly steps can be reduced. Further, the cylinder head 24 force stopper mounting portion having a relatively complicated structure is eliminated, and the weight of the cylinder head 24 can be reduced and the structure can be simplified. Furthermore, the cylinder head 24 and the stopper piece 72 have a separate structure, so that it is not necessary to prevent damage to the stopper piece 72 during engine assembly. In addition, since the stopper mounting portion 73 is formed on the camshaft holder 65, the number of parts around the cylinder head 24 can be reduced and the cost can be reduced.

It should be noted that the present invention is not limited to the above-described embodiment, and may be applied to, for example, an engine having a plurality of at least one of the intake and exhaust valves, a multi-cylinder engine, or a water-cooled engine.

The configuration in the above embodiment is an example of the present invention, and it can be applied to various vehicles such as a starter type vehicle, and various modifications can be made without departing from the gist of the present invention. Nah ...

Industrial applicability

[0043] According to the present invention, the stopper mechanism can be assembled in advance in the camshaft holder, and the number of engine assembly steps can be reduced. In addition, since the stopper mounting portion is eliminated from the cylinder head having a relatively complicated structure, the weight of the cylinder head can be reduced and the structure can be simplified. In addition, the cylinder head and the stopper mechanism have a separate structure, making it unnecessary to prevent damage to the stopper mechanism during engine assembly.

Claims

The scope of the claims

[1] A cylinder head having an intake / exhaust port therein, an intake / exhaust valve for opening / closing the intake / exhaust port, a camshaft rotatably supported by the cylinder head and operating the intake / exhaust valve, and the cylinder head And a camshaft holder that supports the camshaft; and a decompression apparatus for an internal combustion engine, the deconvolution apparatus comprising:

A deconvolution mechanism that is attached to the camshaft and that incorporates a one-way clutch that transmits torque only when the camshaft is reversely rotated;

And a stopper mechanism which is attached to the camshaft holder and stops the operation of the decompression mechanism when the camshaft is rotated forward.

[2] The deconvolution apparatus according to claim 1, wherein the stopper mounting portion force for mounting the stopper mechanism is integrally formed with the camshaft holder.

[3] The deconvolution apparatus according to claim 1 or 2, wherein the camshaft holder has a separate structure from the cylinder head.