JP6088460B2 - Internal combustion engine - Google Patents

Description

  The present invention relates to an internal combustion engine having a cylinder having a combustion chamber and a piston that is slidable back and forth at the inner periphery of the cylinder.

  In a conventional four-cycle internal combustion engine, a linear motion rotation conversion mechanism that converts a reciprocating motion of a piston into a rotational motion of a crankshaft (crankshaft) serving as an engine main shaft via a connecting rod (connecting rod) is generally used. Widely adopted.

JP-A-8-178010

  However, in the above-described conventional linear motion rotation conversion mechanism, when the four-cycle internal combustion engine performs the intake stroke, the compression stroke, the expansion stroke, and the exhaust stroke, the piston reciprocates twice between the top dead center and the bottom dead center. In the meantime, the crankshaft rotates twice.

  That is, in such a four-cycle internal combustion engine, the piston is generally reciprocated once (corresponding to two strokes) to rotate the crankshaft once. There was a problem that the conversion efficiency could not be improved any more.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an internal combustion engine that can convert a linear motion of a piston into a rotational motion more efficiently.

To achieve this object, an internal combustion engine according to a first aspect of the present invention includes a cylinder having a combustion chamber, a piston that is slidable back and forth on the inner periphery of the cylinder, and a rotational output that is rotationally driven by the reciprocating movement of the piston. And an outer diameter smaller than the inner diameter of the piston so that it can be loosely inserted into the cylinder and connected to the base end of the piston so as to be integrated with the piston. And a slider member that reciprocates in a direction that coincides with the axial direction of the rotary output shaft, and one of the slider member and the rotary output shaft that spirally continues from one end side to the other end side in the axial direction. A forward groove that is connected in communication with both ends of the forward groove in the axial direction and is spirally continuous from one end side to the other end side in the opposite direction to the forward groove. Spiral made by connecting the groove The slider in a state in which one ring groove or two or more linear motion rotation conversion grooves provided at different positions at equal angular intervals around the axis and a spiral circulation groove of the linear motion rotation conversion groove are engaged. One or two or more engaging members provided on the other of the member and the rotation output shaft, and the rotation of the slider member provided with the engaging member or the linear motion rotation conversion groove are controlled around the axis of the slider member. A guide member that allows reciprocal movement and guides the reciprocating movement, and the engagement member is reciprocated integrally with the piston so that the engaging member is Relative reciprocation between the axial direction one end side and the other end side along the spiral circulation groove of the linear motion rotation conversion groove, and relative reciprocation along the spiral circulation groove of the engaging member By the rotation output The is for driving rotation.

  An internal combustion engine according to a second aspect of the invention is the internal combustion engine according to the first aspect, wherein the cylinder whose inner peripheral surface is cylindrical and the piston whose outer peripheral surface fitted into the cylinder so as to be reciprocally slidable are cylindrical. And.

  An internal combustion engine of a third invention is the internal combustion engine of the first or second invention, wherein the slider member is inserted into and removed from the inner peripheral portion of the rotary output shaft, or the rotary output shaft is inserted into and removed from the inner peripheral portion of the slider member. One of the linear motion rotation conversion groove or the engagement member is provided on the slider member or the rotation output shaft that is disposed on the inner side of the slider member or the rotation output shaft. Of these, the linear motion rotation conversion groove or the other of the engaging members is provided on the outer side.

  An internal combustion engine of a fourth invention is the internal combustion engine of any one of the first to third inventions, wherein the tip end portion of the engagement member is formed in a hemispherical shape, and the spiral circulation groove has a semicircular shape in a sectional view. It has a groove bottom shape.

  An internal combustion engine according to a fifth aspect of the present invention is the internal combustion engine according to any one of the first to fourth aspects, wherein the internal combustion engine is a multi-cylinder internal combustion engine and the rotation of the rotation output shaft of each cylinder is transmitted. A main shaft and a transmission mechanism for transmitting the rotation output shaft of each cylinder to the engine main shaft are provided.

  An internal combustion engine of a sixth invention is a flywheel attached to the rotation output shaft in the internal combustion engine of any one of the first to fourth inventions or attached to the engine main shaft of the internal combustion engine of the fifth invention. I have.

  According to the internal combustion engine of the present invention, the linear motion rotation conversion groove has one or more spiral circulation grooves, and the spiral circulation groove has one end in the axial direction around one of the slider member and the rotation output shaft. A forward groove provided spirally from the other end to the other end and a return groove provided spirally opposite the forward groove from the one axial end to the other end Since it is a closed loop groove connected at both ends in the direction, an engagement member that engages with the spiral circulation groove is provided on the other of the slider member or the rotary output shaft, and the slider member is connected to the piston. The linear motion of the slider member that reciprocates together with the rotary output shaft can be converted into the rotational motion of the rotary output shaft.

  Here, when the slider member moves forward together with the piston, the engaging member engaged with the linear motion rotation conversion groove moves in the forward movement groove of the spiral circulation groove from one end side in the axial direction of the slider member or the rotation output shaft. The rotation output shaft is rotated in a certain direction by relatively moving toward the other end side.

  On the other hand, when the slider member moves backward together with the piston, the engaging member engaged with the linear motion rotation conversion groove moves in the backward movement groove of the spiral circulation groove in the other axial end side of the slider member or the rotation output shaft. The rotation output shaft is further rotated in a fixed direction by relatively moving from one end toward the other end. That is, the rotary output shaft is continuously rotated in the same direction by the reciprocating movement of the piston.

  In particular, the number of spiral turns of the forward groove and the backward groove (the number of times the groove spirally turns around the axis of the slider member or the rotation output shaft (for example, a natural number of 1 or more); the same shall apply hereinafter). In the above case, the forward and backward movements of the piston cause the rotation output shaft to make one or more rotations during the forward movement and the backward movement, respectively, and as a result, the piston can perform two or more rotations in one reciprocating operation (two strokes). Become. In other words, the sum of the number of helical turns of the forward movement groove and the number of helical turns of the backward movement groove corresponds to the rotation number of the rotation output shaft when the piston reciprocates once.

  Therefore, according to the internal combustion engine of the present invention, when the piston operates for one stroke (one cycle) of four cycles, the rotation output shaft can be rotated once or more, so that the conventional connecting rod and crankshaft can be In the case of the linear motion rotation conversion mechanism used, the linear motion of the piston is more efficiently converted to the rotational motion of the rotational output shaft, compared to a half rotation of the crankshaft in one cycle of the piston operation. It will be possible.

  In addition, the slider member is guided through the guide member for reciprocating movement in the axial direction, and the rotation around the axis is regulated via the guide member. It can be prevented from rotating together with the shaft. Therefore, the slider member does not rotate around its axis, and as a result, it is possible to prevent the piston connected to the slider member from idling in the cylinder.

  For this reason, in order to prevent idling of the piston in the cylinder, it is not necessary to bother to form the cylinder inner circumference and the piston into a non-cylindrical shape such as an elliptical cylinder, so the cylinder and the piston must be non-cylindrical. It is possible to prevent uneven thermal expansion caused by the above.

  Note that, for example, the number of spiral revolutions of the forward groove and the number of spiral revolutions of the return groove are not necessarily the same, and may be different, for example, the number of spiral revolutions of the forward groove is two rounds. If the number of spiral turns is one, the rotation output shaft rotates twice when the piston moves forward, and the rotation output shaft rotates once when the piston moves backward one time.

  According to the internal combustion engine of the present invention, the number of revolutions of the rotation output shaft with respect to the reciprocation (two cycles (two strokes)) of the piston is set to 1 by appropriately setting the number of spiral turns of the spiral circulation groove of the linear motion rotation conversion groove. Compared to the conventional reciprocating motion of the piston converted into one rotation of the crankshaft by the linear motion rotation conversion mechanism using the connecting rod and the crankshaft, the linear motion of the piston can be exceeded. There is an effect that it can be converted into rotational motion more efficiently.

It is sectional drawing which showed the internal structure of the 4-cylinder type | mold 4 cycle internal combustion engine which is one Example of the internal combustion engine of this invention. It is sectional drawing in the AA of FIG. It is sectional drawing in the BB line of FIG. 1 is a structural diagram of an engine valve system. FIG. It is an arrangement view of a valve system in a cylinder head. It is a side view of a rotation output shaft, and shows an engagement state between a pair of engagement protrusions and a linear motion rotation conversion groove. It is explanatory drawing which showed the state which the arbitrary camshaft rotated 90 degrees at a time. It is the figure which showed the relationship between the stroke of each cylinder, and the rotation angle of an engine main shaft. It is sectional drawing of the engine of 2nd Example. It is sectional drawing which illustrated partially the internal structure of the engine of 2nd Example. It is sectional drawing which showed the engagement state of a pair of engagement protrusion and direct-acting rotation conversion groove | channel of the engine of 3rd Example.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. The internal combustion engine 1 of the present embodiment is rotationally driven by a cylinder (cylinder) 3 having a combustion chamber 2, a piston 4 slidable in a reciprocating manner on the inner peripheral portion of the cylinder 3, and a reciprocating movement of the piston 4. A rotation output shaft 5 is provided, and a slider member 6, a linear motion rotation conversion groove 7, an engagement member 8, and a guide member 9 are further provided.

  The linear motion rotation converting groove 7 is provided on the outer peripheral portion of the rotation output shaft 5. The linear motion rotation conversion groove 7 has two spiral circulation grooves 7a and 7b. The two spiral circulation grooves 7 a and 7 b are provided at different positions at equal angular (180 °) intervals in the outer peripheral direction of the rotation output shaft 5. The two spiral circulation grooves 7a and 7b both cross each other in order to spiral around the outer periphery of the rotary output shaft 5.

  Note that the number (number) of spiral circulation grooves of the linear motion rotation conversion groove 7 is not necessarily two, and may be one or three or more, for example. Similarly, when there are three or more spiral circulation grooves, each of the spiral circulation grooves is provided around the axis of the rotation output shaft 5 (outer circumferential direction) at different positions at equal angular intervals. In the case of a book, the spiral circulation grooves are arranged in different positions at 120 ° intervals in the outer circumferential direction of the rotary output shaft 5.

  The spiral circulation grooves 7a and 7b are formed so that the forward movement groove 7c through which the engagement member 8 passes when the piston 4 and the slider member 6 move forward, and the engagement member 8 when the piston 4 and the slider member 6 move backward. The reciprocating groove 7d that passes therethrough is connected at both axial ends of the rotary output shaft 5 to form a closed loop circulation groove. When the number of spiral turns is ½ or more, the forward groove 7c and the backward groove 7d of one spiral circulation groove 7a, 7b intersect one another at the outer peripheral portion of the rotation output shaft 5. It will be possible.

  The forward movement groove 7c is continuously formed in a spiral shape from one end side in the axial direction of the rotation output shaft 5 to the other end side. The backward movement groove 7d is continuously formed in a spiral shape from one end side in the axial direction of the rotation output shaft 5 to the other end side in the opposite direction to the forward movement groove 7c. Further, the forward groove 7 c and the backward groove 7 d that are paired with each other are formed in a closed loop shape by being connected to each other at both axial ends of the rotary output shaft 5.

  The rotation output shaft 5 is detachably disposed on the inner peripheral portion 6a of the slider member 6. The rotation output shaft 5 that is disposed inside the slider member 6 and the rotation output member is provided with the linear motion rotation conversion groove 7 as described above, and the slider member 6, the rotation output shaft 5, An engaging member 8 is provided on the slider member 6 that is disposed outside the slider member 6.

  The slider member 6 is integrally connected to the base end portion of the piston 4 and reciprocates together with the piston 4 in a direction coinciding with the axial direction of the rotary output shaft 5. The slider member 6 is provided with two engaging members 8, 8. Each of the engaging members 8, 8 is each of two spiral circulation grooves 7 a, 7 b in the linear motion rotation conversion groove 7. Is engaged.

  The guide member 9 is a rotation restricting means for restricting the rotation of the slider member 6 around the axis. However, the guide member 9 allows the slider member 6 to reciprocate in a direction coinciding with the axial direction of the rotary output shaft 5 and guides (guides) the reciprocation of the slider member 6.

  Thus, although the slider member 6 is restricted in rotation by the guide member 9, the rotation output shaft 5 is rotatable (rotatable). The rotation output shaft 5 is engaged with the engaging members 8 and 8 provided on the slider member 6 with respect to the helical circulation grooves 7a and 7b of the linear motion rotation converting groove 7 provided on the outer peripheral portion thereof. It is in the state. The rotary output shaft 5 is rotationally driven by the slider member 6 reciprocating integrally with the piston 4 while the engaging members 8 and 8 are engaged with the spiral circulation grooves 7a and 7b.

  The cylinder 3 has a cylindrical inner peripheral surface, and the piston 4 has a cylindrical shape whose outer peripheral surface matches the inner peripheral surface of the cylinder 3. The piston 4 is fitted in the inner periphery of the cylinder 3 so as to be slidable back and forth.

  The two engaging members 8 and 8 are formed in a hemispherical shape at the tip end portions engaged in the spiral circulation grooves 7a and 7b of the linear motion rotation conversion groove 7, and the spiral circulation grooves 7a and 7b are viewed in cross section. It has a groove bottom shape with a semicircular arc shape. The engaging members 8, 8 are projected from the inner peripheral portion 6 a of the slider member 6 toward the outer peripheral portion of the rotary output shaft 5. The slider member 6 is also a supporting member that supports the two engaging members 8, 8, and supports the two engaging members 8, 8 at equiangular intervals in the circumferential direction of the slider member 6. Yes. The slider member 6 is connected and fixed to the bottom of the piston 4.

  Note that the number of engaging members is not necessarily two, but may be, for example, one or three or more. When there are three or more engaging members, the number of spiral circulation grooves (number) Will also be three. Further, when there are three or more engaging members, the respective engaging members are protruded around the rotation output shaft 5 at different equiangular intervals. For example, when there are three engaging members, each engaging member is protruded around the rotation output shaft 5 at different positions at 120 ° intervals.

  The slider member 6 is formed in a cylindrical shape or an annular shape that can be fitted on the rotary output shaft 5. On the inner peripheral portion 6 a of the slider member 6, two engaging members 8, 8 are projected toward the outer peripheral surface of the rotary output shaft 5 at equiangular intervals in the circumferential direction.

  The rotary output shaft 5 is detachably engaged with the inner peripheral portion 6a of the slider member 6, and when the slider member 6 reciprocates together with the piston 4, the two engaging members 8, The rotary output shaft 5 is rotated by the inner peripheral portion 6 a of the slider member 6 through the engagement of the two spiral circulation grooves 7 a and 7 b of the linear motion rotation converting groove 7.

  Further, the internal combustion engine 1 may be a multi-cylinder internal combustion engine having two or more cylinders. Thus, when the internal combustion engine 1 has multiple cylinders, the rotation (force) of the rotation output shaft 5 of each cylinder is transmitted to the engine main shaft 10 via the transmission mechanism 11. The rotational power of the internal combustion engine 1 is output to an external device such as a power train through the engine main shaft 10.

  By the way, when the internal combustion engine 1 is a single cylinder, the rotary output shaft 5 itself may be used as the engine main shaft 10 and a flywheel 12 may be attached thereto. When the internal combustion engine 1 is a multi-cylinder having two or more cylinders, The flywheel 12 may be attached to the engine main shaft 10 to which the rotational force of the rotation output shaft 5 is transmitted via the transmission mechanism 11. Thus, by attaching the flywheel 12, the rotational inertia of the engine main shaft 10 can be stabilized.

Although the embodiment of the internal combustion engine 1 of the present invention has been described so far, the present invention is not necessarily limited to this embodiment. Here, in the above embodiment,
(1) The rotary output shaft 5 is detachably disposed on the inner peripheral portion 6 a of the slider member 6, and the linear rotation conversion groove 7 is provided on the outer peripheral portion of the rotary output shaft 5. The engaging members 8 and 8 are provided in the part 6a, respectively.
(2) The rotary output shaft 5 is detachably disposed on the inner peripheral portion 6 a of the slider member 6, and the engaging members 8, 8 are connected to the outer peripheral portion of the rotary output shaft 5. The linear motion rotation converting groove 7 may be provided in the part 6a,
(3) After the slider member 6 is detachably disposed on the inner peripheral portion of the rotary output shaft 5, the linear motion rotation conversion groove 7 is provided on the outer peripheral portion of the slider member 6, and the inner peripheral portion of the rotary output shaft 5. The engaging members 8 and 8 may be provided respectively.
(4) After the slider member 6 is detachably disposed on the inner peripheral portion of the rotary output shaft 5, the engaging members 8 and 8 are connected to the outer peripheral portion of the slider member 6, and the inner peripheral portion of the rotary output shaft 5. The linear motion rotation conversion grooves 7 may be provided respectively.

  FIG. 1 is a cross-sectional view showing the internal structure of a four-cylinder four-cycle internal combustion engine 1 (hereinafter simply referred to as “engine”) which is an embodiment of the internal combustion engine 1 of the present invention. As shown in FIG. 1, the engine 1 includes a cylinder block 13, a cylinder head 14, a rotor block 15, and a rotor cover 16.

  A cylinder head 14 is provided on the distal end side of the cylinder block 13, a rotor block 15 is provided on the proximal end side of the cylinder block 13, and a rotor cover 16 is provided on the proximal end side of the rotor block 15 via fasteners such as bolts and nuts. And fastened. Gaskets 17 are interposed between the cylinder block 13 and the cylinder head 14, between the cylinder block 13 and the rotor block 15, and between the rotor block 15 and the rotor cover 16.

  The cylinder block 13 is provided with cylinders 3 for four cylinders, and the cylinder head 14 is provided with intake / exhaust valves 18, 19 corresponding to the respective cylinders 3. The intake port 20 and the exhaust port 21 are opened and closed. Around each cylinder 3 in the cylinder block 13, a water jacket 23 is provided as a coolant circulation passage with a cylinder peripheral wall portion 22 therebetween.

  The piston 4 is fitted in the cylinder 3 so as to be slidable back and forth. The outer peripheral shape of the piston 4 is a columnar shape, and a cylindrical space is formed on the inner periphery of the cylinder 3. A plurality of annular piston rings 24 are fitted on the outer periphery of the tip of the piston 4. A slider rod 6 is coaxially connected to the base end portion of the piston 4. A male screw portion 6 c is formed at the tip end of the slider rod 6, and this male screw portion 6 c is screwed and connected to the base end portion of the piston 4.

  The slider rod 6 has an outer diameter smaller than the inner diameter of the cylinder 3 and can be freely inserted into the cylinder 3. Further, an inner peripheral hole 6 a into which the rotary output shaft 5 coaxially arranged with the slider rod 6 can be inserted and removed is formed in the inner peripheral portion of the slider rod 6. The inner peripheral hole 6 a of the slider rod 6 forms a cylindrical space from the circular opening at the center of the base end surface of the slider rod 6 toward the tip of the slider rod 6.

  An arm portion 6b extends outwardly from the outer periphery of the base end of the slider rod 6, and a guide rod 9 is engaged with and penetrates the arm portion 6b in the thickness direction of the arm portion 6b. Four guide rods 9 are arranged for the slider rod 6 per cylinder (one), and in the case of the four-cylinder internal combustion engine 1 of this embodiment, 16 guide rods 9 are used. Yes.

  The guide rod 9 has an axial center facing the piston 4, the slider rod 6, and the rotary output shaft 5, and the arm portion 6 b of the slider rod 6 can slide back and forth in the axial direction of the guide rod 9. ing. One end of the guide rod 9 in the axial direction is fixed to the cylinder block 13, and the other end in the axial direction is fixed to the base end of the rotor block 15.

  The buffer elastic springs 25 are compression coil springs and are wound around the outer periphery of each guide rod 9 by two. The buffer elastic spring 25 is wound around one end side and the other end side in the axial direction of the guide rod 9 with the arm portion 6b of the slider rod 6 interposed therebetween.

  Of the two buffer elastic springs 25, 25 wound around each guide rod 9, one buffer elastic spring 25 is on one end side in the axial direction of the guide rod 9, and the end on the slider rod 6 side is a free end. The cylinder block 13 side end is a fixed end fixed to the cylinder block 13. The other end of the buffer elastic spring 25 is a free end at the slider rod 6 side and a fixed end at the rotor cover 16 side fixed to the rotor block 15.

  Therefore, when the slider rod 6 reciprocates, the arm portion 6b of the slider rod 6 presses the buffer elastic spring 25 and compresses and deforms on one end side and the other end side of the rotation output shaft 5 in the axial direction. The slider rod 6 is decelerated and buffered through the elastic restoring force of the buffer elastic spring 25 accompanying this compression deformation.

  The two engaging protrusions 8 and 8 are provided so as to protrude inward from the inner peripheral surface of the slider rod 6. The hemispherical tips of the engaging protrusions 8 and 8 have a shape that matches the semicircular shape of the cross-sectional view of the groove section of the spiral circulation grooves 7a and 7b, and each spiral circulation groove of the linear motion rotation conversion groove 7 7a and 7b are engaged. The shaft portion of the engagement protrusion 8 passes through the peripheral wall of the cylindrical shaft of the slider rod 6. The engagement protrusions 8 and 8 are fastened to the peripheral wall of the cylindrical shaft of the slider rod 6 by a locking nut 26 screwed into the shaft portion. A flange 8a is provided around the front end of the engaging protrusion 8 to prevent it from coming off.

  The rotation output shaft 5 is a stepped shaft in which a cylindrical first shaft portion 5a and a second shaft portion 5b are coaxially connected, and two spiral circulation grooves 7a are formed on the outer peripheral surface of the first shaft portion 5a. 7b are recessed. The spiral circulation grooves 7a and 7b each have one spiral turn. That is, when the piston 4 moves in one stroke (one forward or backward movement), the rotation output shaft 5 rotates once. The engagement protrusions 8 and 8 are disposed at different positions by 180 ° in the circumferential direction of the slider rod 6, and the spiral circulation grooves 7 a and 7 b are similarly recessed at 180 ° positions in the circumferential direction of the rotary output shaft 5. It is installed.

  The first shaft portion 5a of the rotation output shaft 5 is connected to the slider rod 6 via the engagement protrusions 8 and 8, and the second shaft portion 5b of the rotation output shaft 5 is connected to the rotor block 15 via a bearing. It is pivotally supported. The rotor block 15 is formed with a boss portion 15a that penetrates and supports the rotation output shaft 5 of each cylinder.

  The second shaft portion 5 b passes through the boss portion 15 a of the rotor block 15, and stopper collars 27 that prevent removal from the rotor block 15 are fixed to both end portions in the axial direction. Each stopper collar 27 abuts on the rotor block 15 and sandwiches the rotor block 15, so that the rotation output shaft 5 is positioned with respect to the rotor block 15.

  The transmission mechanism 11 includes a driving gear 11a and a driven gear 11b that mesh with each other. The driving gear 11 a is a spur gear that is pivotally attached to the end of the rotary output shaft 5 on the second shaft portion 5 b side, and the driven gear 11 b is a spur gear that is pivotally attached to the base end portion of the engine main shaft 10. . The driving gear 11 a is a spur gear for transmitting the rotation of the rotation output shaft 5 to the engine main shaft 10. The engine main shaft 10 is rotated via a driving gear 11a and a driven gear 11b that rotate the rotation output shaft 5.

  The engine main shaft 10 is disposed at the center position of each cylinder portion. The front end of the engine main shaft 10 extends through the cylinder block 13 to the cylinder head 14, and the base end portion of the engine main shaft 10 protrudes outward from the rotor block 15. The rotor block 15 has a boss portion 15 a at the base end side thereof encapsulated by a rotor cover 16. The engine main shaft 10 penetrates the rotor block 15 and the rotor cover 16 and protrudes outward, and is connected to a power train (external device) (not shown).

  The engine main shaft 10 is also disposed through the cylinder block 13 and the cylinder head 14, and is rotatably supported by the cylinder head 14, the rotor block 15 and the rotor cover 16 via bearings. A large-diameter flywheel 12 is disposed in the rotor cover 16, and the flywheel 12 is attached to the engine main shaft 10.

  2 is a cross-sectional view taken along line AA in FIG. As shown in FIG. 2, the cylinders 3 are arranged at equiangular intervals around the center of the cylinder block 13, and the engine main shaft 10 passes through the center of the cylinder block 13. Each cylinder 3 is provided at a position equidistant from the center of the engine main shaft 10, and by disposing each cylinder 3 on the circumference centering on the engine main shaft 10, the arrangement space of the cylinder 3 is reduced. ing.

  Four arm portions 6 b extend from the outer periphery of the slider rod 6. The arm portion 6b is formed at equiangular intervals in the circumferential direction of the slider rod 6, and the guide rod 9 passes through the tip portion. The four guide rods 9 are arranged at equiangular intervals on the same circumference around the axis of the slider rod 6. The two engaging protrusions 8 and 8 are arranged at equiangular intervals on the outer periphery of the slider rod 6 and are fixed at positions facing each other.

  The first shaft portion 5a of the rotary output shaft 5 is loosely inserted in the inner peripheral hole 6a of the slider rod 6, and each spiral circulation of the linear motion rotation conversion groove 7 provided in the recess in the first shaft portion 5a. Engaging protrusions 8 and 8 are engaged with the grooves 7a and 7b, respectively. A rotor block 15 is disposed on the back side of the slider rod 6, and a driving gear 11 a and a driven gear 11 b are disposed on the further back side of the rotor block 15. The driving gear 11a is arranged in a planetary shape around the driven gear 11b.

  The driving gear 11a and the driven gear 11b are spur gears having the same specifications (referred to as tooth profile, module, number of teeth, pressure angle, reference pitch circle diameter, tooth thickness, etc.). For this reason, the rotational speed of each driving gear 11a is transmitted to the driven gear 11b at the same rotational speed, and the rotation of each rotational output shaft 5 is transmitted to the engine main shaft 10 without being accelerated or decelerated. . However, the rotation directions of the rotation output shafts 5 are the same, and the rotation direction of the engine main shaft 10 is rotated in the opposite direction to the rotation output shafts 5.

  3 is a cross-sectional view taken along line BB in FIG. As shown in FIG. 3, in the cylinder block 13, a water jacket 23 is formed around each cylinder 3, and the end of the guide rod 9 is fixed avoiding the water jacket 23.

  FIG. 4 is a structural diagram of the valve system 30 of the engine 1. As shown in FIG. 4, the valve system 30 is accommodated in the cylinder head 14 attached to the cylinder head 14, and is mounted on a cam housing (not shown). In FIG. 4, the SOHC direct acting valve system 30 will be described.

  This direct acting valve system 30 mainly includes an intake valve 18 and an exhaust valve 19 provided for each cylinder of the engine 1, in addition to the first gear 31a of the timing gear train 31 that is mounted on the engine main shaft 10. A tappet (valve lifter) 32, a camshaft 33, and second to fourth gears 31 b to 31 d of the timing gear train 31 are provided. The valve system 30 transmits the rotation of the engine main shaft 10 to the camshaft 33 via the timing gear train 31, and transmits the rotation of the camshaft 33 to the intake valve 18 and the exhaust valve 19 via the tappet 32. The intake valve 18 and the exhaust valve 19 are alternately opened and closed.

  A valve spring 34 is wound around the valve system 30 of the intake valve 18 and the exhaust valve 19, and a tappet 32 is attached to the upper end of the valve system 30. The valve spring 34 is interposed between the cylinder head 14 and the tappet 32 in a compressed state, and applies a biasing force that presses the umbrella portions of the valves 18 and 19 against the opening edges of the intake port 20 and the exhaust port 21. ing.

  The timing gear train 31 transmits the rotation of the engine main shaft 10 to the camshaft 33 to adjust the opening / closing timing of the intake valve 18 and the exhaust valve 19. Since the rotation is made four times, the reduction ratio of the timing gear train 31 is 1/4. The timing gear train 31 is attached to a first gear 31a of a spur gear that is attached to the engine main shaft 10, a second gear 31b of a spur gear that is engaged with the first gear 31a, and the same rotation shaft. A third gear 31c, which is a bevel gear, and a fourth gear 31d, which is a bevel gear that is meshed with the third gear 31c and axially attached to the camshaft 33, are provided.

  FIG. 5 is a layout diagram of the valve system 30 in the cylinder head 14, and illustration of ignition plugs disposed in each cylinder is omitted. As shown in FIG. 5, the valve system 30 includes a first gear 31 a that is attached to the engine main shaft 10 at the center of the cylinder head 14, and the second gear 31 b of each cylinder is connected to the first gear 31 a. It is in mesh.

  The four second gears 31b of the timing gear train 31 are arranged in a planetary shape at equiangular intervals on a circumference centered on the first gear 31a. A third gear 31c is attached to the rotation shaft of each second gear 31b, and a fourth gear 31d is engaged with each third gear 31c. Each fourth gear 31d is pivotally attached to the camshaft 33 of each cylinder.

  Each camshaft 33 is integrally formed with an intake cam 33a and an exhaust cam 33b. The intake cam 33a is connected to the tappet 32 of the intake valve 18, the exhaust cam 33b is connected to the tappet 32 of the exhaust valve 19, and the valve spring 34 is connected to the camshaft 33. Each is in pressure contact via an urging force. Further, the arrangement method of the intake port 20 and the exhaust port 21 is a cross flow method in which the cylinders 3 face each other in the diameter direction.

  With reference to FIG. 6, the process of converting the linear motion of the piston 4 into the rotational motion of the rotary output shaft 5 using the pair of engaging protrusions 8 and 8 and the linear motion rotation converting groove 7 will be described. FIG. 6 is a side view of the rotation output shaft 5 and illustrates the engagement state between the pair of engagement protrusions 8 and 8 and the linear motion rotation conversion groove 7. In particular, FIG. 6A to FIG. 6E illustrate a state in which the rotation output shaft 5 is rotated by 90 °.

  For convenience, in FIG. 6 and the description thereof, the engagement protrusions 8 and 8 engaged with the spiral circulation grooves 7a and 7b described above are referred to as “engagement protrusions 8A”. The one that is engaged with the spiral circulation groove 7b is referred to as “engagement protrusion 8B”.

  As shown in FIG. 6A, the positions of the pair of engaging protrusions 8A and 8B are 180 ° different from each other in the circumferential direction of the rotation output shaft 5, and one engagement protrusion 8A is located on the rotation output shaft 5. On the side surface (lower side in FIG. 6), the other engaging projection 8B is located on the lower side surface (upper side in FIG. 6) of the rotation output shaft 5.

  In the engine 1 of the present embodiment, the pair of engaging protrusions 8A and 8B are fixed to the slider rod 6 and the slider rod 6 is restricted by the four guide rods 9, so that it is shown in FIG. The vertical positional relationship between the pair of engaging protrusions 8A and 8B does not change. Further, since the slider rod 6 reciprocates in the left-right direction in FIG. 6 together with the piston 4, the pair of engaging protrusions 8A and 8B move in the left-right direction in FIG. The axial movement of the output shaft 5 is restricted via the rotor block 15 and the stopper collar 27.

  As shown in FIG. 6, the slider rod 6 moves in the forward movement direction (in the direction of arrow X1 in FIG. 6) as the piston 4 moves, and the pair of engaging protrusions 8A and 8B move from the position shown in FIG. When moving (forward movement) to the position of FIG. 6B, the rotation output shaft 5 is rotated by 90 °. Subsequently, when the pair of engaging protrusions 8A and 8B are moved (moved forward) from the position of FIG. 6B to the position of FIG. 6C by the movement of the slider rod 6, the rotation output shaft 5 is further rotated by 90 ° ( (It corresponds to 180 ° from the position of FIG. 6A).

  Further, when the pair of engaging protrusions 8A and 8B move (forward) from the position of FIG. 6 (c) to the position of FIG. 6 (d) by the forward movement of the slider rod 6, the rotation output shaft 5 further moves 90. It is rotated (corresponding to 270 ° from the position of FIG. 6A). Further, when the pair of engaging protrusions 8A and 8B are moved (forward movement) from the position of FIG. 6 (d) to the position of FIG. 6 (e) by the forward movement of the slider rod 6, the rotation output shaft 5 is further 90 °. (It corresponds to 360 ° from the position of FIG. 6A).

  That is, the slider rod 6 and the pair of engaging protrusions 8A and 8B move the forward movement grooves 7c and 7c of the linear motion rotation conversion groove 7 from one end side (left side in FIG. 6) to the other end side (right side in FIG. 6). The rotation output shaft 5 is rotated 360 °.

  Thereafter, as the piston 4 moves, the slider rod 6 moves in the backward movement direction (in the direction of arrow X2 in FIG. 6), and the pair of engaging protrusions 8A and 8B move from the position of FIG. 6 (e) to FIG. When it is moved (returned) to the position, the rotation output shaft 5 is further rotated 90 ° (corresponding to 450 ° from the position of FIG. 6A). Subsequently, when the pair of engaging protrusions 8A and 8B are moved (returned) from the position of FIG. 6D to the position of FIG. 6C by the movement of the slider rod 6, the rotation output shaft 5 is further rotated by 90 ° ( (It corresponds to 540 ° from the position of FIG. 6A).

  Further, when the pair of engaging protrusions 8A and 8B are moved (returned) from the position shown in FIG. 6C to the position shown in FIG. 6B by the backward movement of the slider rod 6, the rotation output shaft 5 is further turned 90. It is rotated (corresponding to 630 ° from the position of FIG. 6A). Further, when the pair of engaging protrusions 8A and 8B are moved (returned) from the position of FIG. 6B to the position of FIG. 6A by the backward movement of the slider rod 6, and returned to the initial position, The rotation output shaft 5 is further rotated by 90 ° (corresponding to 720 ° from the position of FIG. 6A).

  That is, the slider rod 6 and the pair of engaging protrusions 8A and 8B move the return movement grooves 7d and 7d of the linear motion rotation conversion groove 7 from one end side (right side in FIG. 6) to the other end side (left side in FIG. 6). The rotation output shaft 5 is further rotated 360 °. As a result, when the piston 4 operates in two strokes (two cycles) and reciprocates once, the rotation output shaft 5 is rotated twice.

  Referring to FIG. 7, one rotation of camshaft 33 is performed when an arbitrary piston 4 operates in four cycles (intake stroke, compression stroke, explosion stroke and exhaust stroke), that is, when slider rod 6 reciprocates twice. The operation will be described.

  FIGS. 7A to 7D are explanatory views showing a state when an arbitrary camshaft 33 is rotated by 90 °, and an intake cam 33a and an exhaust cam formed on the camshaft 33. FIG. The position of 33b is illustrated. As shown in FIG. 7A, as described above, the rotation output shaft 5 makes one rotation by the one-stroke operation of the piston 4, so that the engine main shaft 10 also makes one rotation, and as a result, through the timing gear train 31. Thus, the camshaft 33 is rotated 1/4. That is, the intake cam 33a and the exhaust cam 33b are rotated 90 ° (1/4) per stroke.

  Here, the intake cam 33a rotates 90 ° from the position shown in FIG. 7A to the position shown in FIG. 7B, thereby opening and closing the intake valve 18 (intake stroke), and the subsequent compression stroke (see FIG. 7 (b) to 90 ° from the position of FIG. 7 (c), explosion stroke (stroke to 90 ° from the position of FIG. 7 (c) to FIG. 7 (d)) and the exhaust stroke. The intake valve 18 is kept closed during the period (the stroke of 90 ° rotation from the position of FIG. 7D to the position of FIG. 7A).

  Further, the exhaust cam 33b rotates 90 ° from the position shown in FIG. 7D to the position shown in FIG. 7A, thereby opening and closing the exhaust valve 19 (exhaust stroke), and the subsequent intake stroke (FIG. 7). (Stroke that rotates 90 ° from the position of (a) to the position of FIG. 7 (b)), compression stroke (stroke that rotates 90 ° from the position of FIG. 7 (b) to the position of FIG. 7 (c)), and explosion The exhaust valve 19 is kept closed during the stroke (stroke rotated 90 ° from the position shown in FIG. 7C to the position shown in FIG. 7D).

  Thus, the camshaft 33 is provided in a state in which the phase of the intake cam 33a is delayed by 90 ° around the central axis of the camshaft 33 with respect to the exhaust cam 33b. Therefore, for example, the exhaust cam 33b rotates 90 ° from the position shown in FIG. 7D to the position shown in FIG. 7A, and the exhaust cam 33b moves from the start position to the end position of the opening / closing operation (exhaust operation) of the exhaust valve 19. When the rotation is completed, the intake cam 33a arrives at the start position of the opening / closing operation (intake stroke) of the intake valve 18 so as to arrive exactly.

  FIG. 8 is a diagram showing the relationship between the stroke of each cylinder of the engine 1 and the rotation angle of the engine main shaft 10. As shown in FIG. 8, the intake stroke, the compression stroke, the explosion stroke, and the exhaust stroke are repeated in order from the first cylinder to the fourth cylinder of the engine 1. These first to fourth cylinders are ignited in the order of the first cylinder, the second cylinder, the third cylinder, and the fourth cylinder, and perform an explosion stroke. Further, the engine main shaft 10 rotates 360 ° every time each cylinder explodes, and all four cylinders rotate four times through an explosion stroke.

  FIG. 9 is a cross-sectional view of the engine of the second embodiment, and FIG. 10 is a cross-sectional view partially showing the internal structure of the engine of the second embodiment. The engine 40 of the second embodiment is obtained by changing the slider rod guide mechanism with respect to the engine 1 of the first embodiment. In the following, the same parts as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only different parts are described.

  As shown in FIG. 9, according to the engine 40 of the second embodiment, three arm portions 6 b are extended from the outer periphery of the slider rod 6. The arm portion 6b is formed at equiangular intervals in the circumferential direction of the slider rod 6, and a guide rod 9 penetrates the tip portion of the arm portion 6b. The three guide rods 9 are arranged at equiangular intervals on the same circumference around the axis of the slider rod 6.

  Each guide rod 9 is sandwiched between a pair of guide rollers 41, 41, and the pair of guide rollers 41, 41 rolls in contact with the guide rod 9 along the axial direction of each guide rod 9. The pair of guide rollers 41 and 41 are both pivotally supported on the support base 42. Each guide roller 41, 41 is provided with an engaging groove 41a having a semicircular bottom in cross-sectional view that conforms to the cross-sectional shape of the guide rod 9, and is recessed in the outer peripheral surface. 9 is engaged. The support pedestal 42 supports a pair of guide rollers 41, 41 so as to be freely rotatable, and is fixedly attached to the tip of the arm portion 6b.

  As shown in FIG. 10, the pair of guide rollers 41, 41 are formed so as to have the same diameter, and are opposed to each other in the axial direction of the guide rod 9 with the positions of the rotation axes being different. Yes. This is for preventing the paired guide rollers 41 and 41 from interfering with each other.

  FIG. 11 is a cross-sectional view showing an engagement state between the pair of engaging protrusions 8 and 8 and the linear motion rotation converting groove 7 in the engine 50 of the third embodiment. The engine 50 of the third embodiment is a modification of the engine 1 of the first embodiment in which the engagement protrusion and the linear motion rotation conversion groove are changed. In the following, the same parts as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only different parts are described.

  As shown in FIG. 11, according to the engine 50 of the third embodiment, each spiral circulation groove 57a, 57b of the linear motion rotation conversion groove 57 has a semicircular bottom. Vertical planes 51 and 51 are formed on both sides of the groove bottom. The engaging projections 58, 58 have a semispherical surface at the tip thereof that can abut on a semicircular groove bottom of the spiral circulation grooves 57a, 57b, and a cylindrical outer peripheral surface at the tip of the engagement protrusions 58, 58 is formed by the spiral circulation grooves 57a, 57b. It can come into contact with the vertical surfaces 51, 51. The engaging protrusions 58 and 58 are pivotally attached to the slider rod 6 via bearings 52 and 52, and are moved while being engaged with the spiral circulation grooves 57a and 57b. It abuts on the vertical surface of 57b and can freely roll.

  By the rolling of the engagement protrusions 58 and 58, friction with the spiral circulation grooves 57a and 57b is reduced, and wear of the engagement protrusions 58 and 58 and the spiral circulation grooves 57a and 57b can be reduced. In addition, a flange 58a is provided around the distal ends of the engagement protrusions 58 and 58. One side of the flange 58a has a spherical shape, and the other side has a flat shape. The spherical surface of the flange 58 a is adapted to the curvature of the inner peripheral surface of the slider rod 6, and when the engaging protrusions 58, 58 roll in the spiral circulation grooves 57 a, 57 b, the flange 58 a also becomes the inner peripheral surface of the slider rod 6. It is rotated while abutting or sliding on.

  In addition, since the spherical surface of the flange 58a matches the curvature of the inner peripheral surface of the slider rod 6 as described above, the shaft runout can be reduced when the engagement protrusions 58, 58 move in the spiral circulation grooves 57a, 57b. The rotation of the engagement protrusions 58, 58 can be stabilized. In addition, the flange 58a has a spherical surface adapted to the inner peripheral surface of the slider rod 6 and its flat surface is in contact with the rotary output shaft 5, so that the flange 58a is located between the slider rod 6 and the rotary output shaft 5. The engagement protrusions 58 and 58 are difficult to come off.

  Further, by providing a vertical surface on both sides of the semicircular groove bottoms of the spiral circulation grooves 57a and 57b, the groove depth of the spiral circulation grooves 57a and 57b can be increased. 58 and 58 can be engaged deeper into the spiral circulation grooves 57a and 57b, and the engagement protrusions 58 and 58 are difficult to be removed from the spiral circulation grooves 57a and 57b.

  The present invention has been described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be easily made without departing from the spirit of the present invention. It can be guessed.

1,40,50 engine (internal combustion engine)
2 Combustion chamber 3 Cylinder
4 Piston 5 Rotation output shaft 6 Slider rod (slider member)
6a Inner circumference (inner hole)
7, 57 Linear motion rotation conversion grooves 7a, 7b, 57a, 57b Spiral circulation groove 7c Forward motion groove 7d Reverse motion grooves 8, 8, 58, 58 Engaging protrusion (engaging member)
9 Guide rod (guide member)
10 Engine spindle 12 Flywheel

Claims (6)

In an internal combustion engine comprising a cylinder having a combustion chamber, a piston that is reciprocally slidable on the inner periphery of the cylinder, and a rotation output shaft that is rotationally driven by the reciprocating movement of the piston.
The outer diameter of the piston is smaller than the inner diameter of the piston so that it can be loosely inserted into the cylinder, and is connected to the base end of the piston so as to be integrated with the piston and the rotary output shaft. A slider member that reciprocates in a direction that coincides with the axial direction of
One of the slider member and the rotary output shaft is connected in a spiral manner to one end side in the axial direction from one end side to the other end side, and is connected to both ends in the axial direction of the forward groove. One spiral circulation groove formed by connecting the reverse movement groove that is spirally continuous from one end side to the other end side in the axial direction opposite to the movement groove, or is equiangular around the axis A linear motion rotation conversion groove provided at two or more positions at different intervals;
One or more engaging members provided on the other of the slider member or the rotation output shaft in a state of being engaged with the spiral circulation groove of the linear motion rotation converting groove;
A guide member that regulates the rotation of the slider member around the axis provided with the engaging member or the linear rotation conversion groove and permits the reciprocating movement of the slider member to guide the reciprocating movement;
When the slider member guided by the guide member reciprocates integrally with the piston, the engagement member moves along the spiral circulation groove of the linear motion rotation conversion groove, on one end side in the axial direction and the other end. An internal combustion engine characterized in that the rotary output shaft is rotationally driven by a relative reciprocation along the spiral circulation groove of the engaging member. The cylinder having a cylindrical inner peripheral surface;
2. An internal combustion engine as set forth in claim 1, further comprising: a piston having an outer peripheral surface fitted into the cylinder so as to be slidable in a reciprocating manner. The slider member is detachably disposed on the inner peripheral portion of the rotary output shaft, or the rotary output shaft is detachable from the inner peripheral portion of the slider member,
One of the linear motion rotation conversion groove or the engagement member is provided on the slider member or the rotation output shaft that is disposed inside,
3. The internal combustion engine according to claim 1, wherein the slider member or the rotation output shaft is provided on the outer side with the other of the linear motion rotation conversion groove or the engagement member. 4.   The internal combustion engine according to any one of claims 1 to 3, wherein a tip end portion of the engaging member is formed in a hemispherical shape, and the spiral circulation groove has a groove bottom shape having a semicircular arc shape in a sectional view. organ.   The internal combustion engine is a multi-cylinder internal combustion engine, an engine main shaft to which rotation of the rotation output shaft of each cylinder is transmitted, and a transmission mechanism that transmits rotation of the rotation output shaft of each cylinder to the engine main shaft. The internal combustion engine according to any one of claims 1 to 4, further comprising:   A flywheel attached to the rotation output shaft in the internal combustion engine according to any one of claims 1 to 4 or attached to the engine main shaft in the internal combustion engine according to claim 5 is provided. An internal combustion engine.

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