Flywheel housing and engine equipped with flywheel housing

Abstract

To provide a flywheel housing which can inhibit an engine from becoming large and can improve workability, and an engine including the flywheel housing.SOLUTION: A flywheel housing 100 includes a body part 110 disposed in a side of a flywheel 20 closer to an engine 1 and having an accommodation part 11 accommodating the flywheel 20, and a cover part 120 disposed in a side of the flywheel 20 opposite to the engine 1, connected to the body part 110, and having an opening part 125 with an inner diameter less than an outer diameter of the flywheel 20. The cover part 120 is provided with a recessed part 123 recessed in a direction away from the flywheel 20, on a surface 122b, facing the flywheel 20, in a peripheral part of an edge of the opening part 125.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a flywheel housing that houses a flywheel connected to the output shaft of an engine and an engine including the flywheel housing.

Background Art

[0002] A flywheel is connected to a crankshaft, which is one of the output shafts of an engine, and contributes to the smooth rotation of the engine. The flywheel is housed in a flywheel housing provided in the engine block.

[0003] Patent Document 1 discloses an engine including a flywheel housing, a flywheel, and a flywheel cover at the rear end of the engine. In this engine, the flywheel housing has a circular opening on its end face, and the opening is closed by the flywheel cover. The flywheel is housed in the flywheel housing. A through hole is provided in the flywheel cover, and the rotational force of the engine is taken out through this through hole.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The flywheel housing is designed to enclose the outside of the flywheel. Therefore, increasing the size of the flywheel housing leads to an overall increase in engine size. On the other hand, reducing the size of the flywheel housing reduces the distance between the housing and the flywheel, so it is desirable to avoid compromising workability during engine assembly and inspection. Furthermore, having the flywheel housing serve functions other than housing the flywheel is important for saving space in the engine.

[0006] The present invention has been made in view of the above circumstances, and aims to provide a flywheel housing and an engine equipped with a flywheel housing that can suppress the increase in engine size and improve workability. [Means for solving the problem]

[0007] A first aspect of the present invention is a flywheel housing for housing a flywheel connected to the output shaft of an engine, comprising: a main body portion disposed on the engine side of the flywheel and having a housing portion for housing the flywheel; and a cover portion disposed on the opposite side of the flywheel from the engine, connected to the main body portion and having an opening with an inner diameter smaller than the outer diameter of the flywheel, wherein the cover portion is provided with a recess on the surface facing the flywheel at the periphery of the edge of the opening, which is concave in a direction away from the flywheel.

[0008] According to a first aspect of the present invention, a recess is provided on the surface facing the flywheel at the periphery of the edge of the opening of the cover, so that a gap is formed between the cover and the flywheel at the periphery of the edge of the opening, and this gap improves workability.

[0009] A second aspect of the present invention is a flywheel housing characterized in that, in the first aspect of the present invention, the edge of the opening is located on the bottom surface of the recess.

[0010] According to a second aspect of the present invention, since the edge of the opening is located on the bottom surface of the recess, the bottom of the recess is continuous with the edge of the opening, making it easy to access the surface of the cover portion facing the flywheel from the edge of the opening.

[0011] A third aspect of the present invention is a flywheel housing characterized in that, in the first or second aspect of the present invention, a curved surface is provided between the side surface and the bottom surface of the recess.

[0012] According to a third aspect of the present invention, the curved surface between the side and bottom of the recess makes it easier for an operator to make contact with the surface of the recess when they put their hand into it.

[0013] A fourth aspect of the present invention is a flywheel housing characterized in that, in any one of the first to third aspects of the present invention, a curved surface is provided between adjacent sides of the recess.

[0014] According to a fourth aspect of the present invention, the curved surface between adjacent sides of the recess makes it easier for an operator to make contact with the surface of the recess when they put their hand into it.

[0015] A fifth aspect of the present invention is a flywheel housing characterized in that, in any one of the first to fourth aspects of the present invention, a plurality of recesses are provided on the opposing surface on the circumference around the opening, and ribs are provided between adjacent plurality of recesses.

[0016] According to a fifth aspect of the present invention, even if a plurality of recesses are provided on the surface of the cover portion facing the flywheel, the strength of the cover portion is ensured by ribs provided between adjacent recesses.

[0017] A sixth aspect of the present invention is a flywheel housing characterized in that, in the fifth aspect of the present invention, the space between the outer surface of the rib and the bottom surface of the recess is curved.

[0018] According to a sixth aspect of the present invention, since the space between the outer surface of the rib and the bottom surface of the recess is curved, it becomes easier for the worker to make contact with the surface of the rib when they put their hand into the recess.

[0019] A seventh aspect of the present invention is a flywheel housing characterized in that, in the fifth or sixth aspect of the present invention, the tip of the rib in the extending direction is located at the edge of the opening.

[0020] According to a seventh aspect of the present invention, the tip of the rib in the extending direction is located at the edge of the opening, making it easier to access the recess along the rib from the edge of the opening.

[0021] An eighth aspect of the present invention is a flywheel housing characterized in that, in any one of the fifth to seventh aspects of the present invention, the width of the rib narrows in the extending direction.

[0022] According to the eighth aspect of the present invention, the width of the rib narrows in the direction of extension, thereby securing the width at the base of the rib and obtaining a reinforcing effect, while the width of the recess widens towards the edge of the opening, making it easier to insert a hand into the recess from the opening.

[0023] A ninth aspect of the present invention is an engine comprising a flywheel housing for housing a flywheel connected to the output shaft of an engine, wherein the flywheel housing comprises a main body portion disposed on the engine side of the flywheel and having a housing portion for housing the flywheel, and a cover portion disposed on the opposite side of the engine from the flywheel, connected to the main body portion and having an opening with an inner diameter smaller than the outer diameter of the flywheel, wherein the cover portion is provided with a recess on the surface facing the flywheel at the periphery of the edge of the opening, which is concave in a direction away from the flywheel.

[0024] According to the ninth aspect of the present invention, since a concave portion is provided on the opposing surface with the flywheel in the peripheral portion of the edge of the opening of the cover portion, a gap is formed between the cover portion and the flywheel in the peripheral portion of the edge of the opening, and the workability is improved by this gap.

Effect of the Invention

[0025] According to the present invention, it is possible to provide a flywheel housing that suppresses the enlargement of the engine and improves workability, and an engine provided with the flywheel housing.

Brief Description of the Drawings

[0026] [Figure 1] It is a perspective view showing an engine provided with a flywheel housing according to an embodiment of the present invention. [Figure 2] It is an exploded perspective view of the flywheel housing according to this embodiment. [Figure 3] It is a perspective view illustrating a cover portion. [Figure 4] It is a partial cross-sectional view of the cover portion. [Figure 5] It is a perspective view (part 1) illustrating a part of the main body portion. [Figure 6] It is a perspective view (part 2) illustrating a part of the main body portion. [Figure 7] It is a perspective view illustrating a part of the cover portion. [Figure 8] It is a cross-sectional view illustrating a part of the flywheel housing. [Figure 9] It is a perspective view illustrating a support portion provided on the flywheel housing. [Figure 10] It is a side view illustrating a support portion provided on the flywheel housing.

Mode for Carrying Out the Invention

[0027] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments described below are preferred examples of the present invention and are subject to various technically preferred limitations. However, the scope of the present invention is not limited to these embodiments unless otherwise specified in the following description. In addition, similar components are denoted by the same reference numerals in the drawings, and detailed descriptions are omitted as appropriate.

[0028] Figure 1 is a perspective view showing an engine equipped with a flywheel housing according to an embodiment of the present invention. The engine 1 shown in Figure 1 is an internal combustion engine, such as an industrial diesel engine. Engine 1 is a multi-cylinder engine, such as a turbocharged, high-output 3-cylinder or 4-cylinder engine. Engine 1 is installed in industrial machinery such as construction machinery or agricultural machinery. Engine 1 may also be configured as a hybrid drive system by combining a drive charging battery and a drive electric motor.

[0029] Engine 1 comprises a cylinder block 2, a cylinder head 3, a head cover 4, an oil pan 7, a blow-by gas treatment device 10, and a flywheel 20 housed in a flywheel housing 100. In this embodiment, the axial direction of the crankshaft 9, which is the output shaft of engine 1, is referred to as the X direction, one of the directions perpendicular to the X direction (lateral direction) is referred to as the Y direction, and the direction perpendicular to both the X and Y directions (height direction) is referred to as the Z direction. Furthermore, one of the X directions (front of engine 1) is referred to as X1, the other (rear of engine 1) as X2, one of the Y directions is referred to as Y1, the other as Y2, one of the Z directions (above engine 1) as Z1, and the other (below engine 1) as Z2.

[0030] The cylinder head 3 is mounted on top of the cylinder block 2. The head cover 4 is mounted on top of the cylinder head 3. The cylinder block 2 has an upper cylinder 5 and a lower crankcase 6. The oil pan 7 is located at the bottom of the crankcase 6. A piston (not shown) is located inside the cylinder 5. The crankshaft 9 is located inside the crankcase 6. The piston is connected to the crankshaft 9 via a connecting rod (not shown).

[0031] The blow-by gas treatment device 10 is installed inside the head cover 4. The blow-by gas treatment device 10 has the role of separating the blow-by gas into oil and gas from which oil mist has been separated.

[0032] The flywheel 20 is connected to the rear end (X2 side end) of the crankshaft 9, which is one of the output shafts of the engine 1. The flywheel 20 rotates together with the crankshaft 9, and the centrifugal force generated by this rotation smooths the rotational operation of the engine 1.

[0033] The flywheel housing 100, which houses the flywheel 20, is provided at the rear end (X2 side end) of the cylinder block 2. The flywheel housing 100 has a main body portion 110 and a cover portion 120. The main body portion 110 has a housing portion 111 (see Figure 2) for housing the flywheel 20 and is fastened to the cylinder block 2, for example, by bolts. When the flywheel 20 is housed in the housing portion 111, the main body portion 110 is positioned to cover the cylinder block 2 side (X1 side) of the flywheel 20.

[0034] The cover portion 120 is attached to the main body portion 110 so as to face the main body portion 110. The cover portion 120 is attached to the X2 side of the main body portion 110, for example, by bolts. By attaching the cover portion 120 to the main body portion 110, the cover portion 120 is positioned to cover the side of the flywheel 20 opposite to the cylinder block 2 (the X2 side). An opening 125 (see Figure 2) is provided in the center of the cover portion 120. The rotational force of the flywheel 20, i.e., the rotational force of the engine 1, is taken out to the outside through this opening 125.

[0035] Figure 2 is an exploded perspective view of the flywheel housing according to this embodiment. The flywheel housing 100 has a bowl-shaped main body portion 110 and an annular cover portion 120. Inside the bowl-shaped main body portion 110 is a housing portion 111 for housing the flywheel 20. The inner diameter of the housing portion 111 is larger than the outer diameter of the flywheel 20. A hole 115 is provided in the center of the main body portion 110 (the center of the bottom portion of the bowl shape). When the main body portion 110 is attached to the cylinder block 2, the end of the crankshaft 9 is positioned in the center of the hole 115.

[0036] With the main body 110 attached to the rear end of the cylinder block 2, the flywheel 20 is connected to the crankshaft 9. The flywheel 20 is housed in the housing 111 and connected to the crankshaft 9 located in the hole 115. When connecting the flywheel 20 to the rear end of the crankshaft 9, the flywheel 20 may be fixed via a connecting member (for example, a connecting flange) attached to the rear end of the crankshaft 9.

[0037] With the flywheel 20 attached to the housing 111 of the main body 110, the cover 120 is attached to the X2 side of the main body 110. The cover 120 covers the housing 111 of the main body 110. Main body 110 It is attached to the main body 110. Mounting holes 126 are provided around the annular cover portion 120, and the cover portion 120 is fastened to the main body portion 110 by bolts (not shown) through these mounting holes 126.

[0038] An opening 125 is provided in the center of the cover portion 120. The inner diameter of the opening 125 is smaller than the outer diameter of the flywheel 20. As a result, when the cover portion 120 is attached to the main body portion 110, the outer circumference of the flywheel 20 is covered by the cover portion 120. The central portion of the flywheel 20 can be accessed from the outside through the opening 125. Driven equipment that utilizes the rotational force of the engine 1 can obtain the rotational force of the flywheel 20 through the opening 125 of the cover portion 120.

[0039] (Composition of the cover section) Next, the configuration of the cover portion 120 of the flywheel housing 100 will be described. Figure 3 is a perspective view illustrating the cover portion. Figure 3 shows a perspective view of the cover portion 120 with the X1 side facing X2. Figure 4 is a partial cross-sectional view of the cover portion. Figure 4 shows a cross-sectional view of line AA shown in Figure 3. The cover portion 120 has an annular outer circumference portion 121 and an inner circumference portion 122 provided inside the outer circumference portion 121. The inner circumference portion 122 is the portion between the outer circumference portion 121 and the opening 125. The outer circumference portion 121 is provided with a plurality of mounting holes 126 at predetermined intervals. The inner circumference portion 122 is provided with a protrusion 122a that extends along the circumference. The protrusion 122a is used to align the center position when attaching the cover portion 120 to the main body portion 110.

[0040] A recess 123 is provided on the inner circumference 122, on the surface 122b facing the flywheel 20, which is concave in the direction away from the flywheel. Since the bottom surface 123b of the recess 123 is set back toward the X2 side from the facing surface 122b, a gap is formed between the cover portion 120 and the flywheel 20 at the position of the recess 123. This gap provides working space when accessing the flywheel 20 from the X2 side of the cover portion 120 through the opening 125.

[0041] For example, when the cover portion 120 is attached to the main body portion 110, and the worker wants to clean the portion of the flywheel 20 covered by the cover portion 120 or the opposing surface 122b on the back side of the cover portion 120 through the opening 125, the worker can easily reach in by utilizing the gap formed by the recess 123. If the recess 123 is not provided, the gap between the cover portion 120 and the flywheel 20 will be narrow, making it difficult to reach in between the back side of the cover portion 120 (the surface 122b facing the flywheel 20) and the flywheel 20 through the opening 125. In this embodiment, the recess 123 forms a gap between the back side of the cover portion 120 and the flywheel 20, making it easier to reach in this area through the opening 125 and wipe it with a cloth or the like.

[0042] It is preferable to provide a plurality of recesses 123 on the opposing surface 122b of the cover portion 120. The plurality of recesses 123 are arranged along the edge 125a of the opening 125. This improves workability over a wide area of ​​the opposing surface 122b of the cover portion 120.

[0043] Ribs 124 are provided between two adjacent recesses 123 in the multiple recesses 123. That is, each of the multiple recesses 123 and each of the multiple ribs 124 are arranged alternately. The thickness of the cover portion 120 is reduced by providing the recesses 123, but the strength of the cover portion 120 is ensured by providing the ribs 124.

[0044] The recess 123 is positioned such that the edge 125a of the opening 125 lies on the bottom surface 123b of the recess 123. In other words, the recess 123 is positioned along the edge 125a of the opening 125. As a result, the bottom surface 123b of the recess 123 is continuous with the edge 125a of the opening 125, and there is no wall on the side of the edge 125a of the recess 123. This makes it easy to access the opposing surface 122b of the cover portion 120 from the edge 125a of the opening 125.

[0045] Furthermore, if a rib 124 is provided between multiple adjacent recesses 123, the tip 124a of the rib 124 in the extending direction is located at the edge 125a of the opening 125. By having the tip 124a of the rib 124 located at the edge 125a of the opening 125, it becomes easier to access the recesses 123 from the edge 125a of the opening 125 along the rib 124.

[0046] In this case, it is preferable that a curved surface 123c is provided between the side surface 123s and the bottom surface 123b of the recess 123. It is also preferable that a curved surface 123d is provided between adjacent side surfaces 123s of the recess 123. In this way, the spaces between surfaces in the recess 123 are curved surfaces 123c and 123d, making it easier for the worker to make contact with the entire surface of the recess 123 when they put their hand into the recess 123. That is, the corners between adjacent side surfaces 123s and between side surfaces 123s and the bottom surface 123b have relatively large radius surfaces, making it easier for the hand to make contact with the corners and suppressing missed spots during wiping. Note that the recess 123 may consist only of recessed curved surfaces (surfaces that do not include flat surfaces).

[0047] Furthermore, as shown in Figure 4, it is preferable that the space between the outer surface of the rib 124 and the bottom surface 123b of the recess 123 is curved. The outer surface of the rib 124 corresponds to a part of the side surface 123s of the recess 123. In this embodiment, as shown in Figure 4, the rib 124 has a symmetrical (line symmetry with respect to the X direction) mountain shape (for example, a normal distribution) on a plane represented by the X and Z directions. The curved space between the outer surface of the rib 124 (i.e., a part of the side surface 123s of the recess 123) and the bottom surface 123b of the recess 123 makes it easier for an operator to make contact with the surface of the rib 124 when they put their hand into the recess 123.

[0048] The width of the rib 124 (length in the Y direction in Figure 4) is preferably narrowed in the extending direction (direction from the X2 side to the X1 side in Figure 4). This ensures the width at the base of the rib 124 and provides a reinforcing effect, while the width of the recess 123 widens towards the edge 125a, making it easier to insert a hand into the recess 123 from the opening 125.

[0049] (Water drainage mechanism) Next, the drainage mechanism of the flywheel housing 100 will be described. In engine 1, sealing is required at the joints between components, such as between the cylinder block 2 and the cylinder head 3, and between the cylinder head 3 and the head cover 4. One method for inspecting sealing is a submersion test. In the submersion test of engine 1, the flywheel housing 100 is covered to prevent water from entering it. However, even with the cover, some water may enter the flywheel housing 100. After the submersion test, this water needs to be drained from the flywheel housing 100. The flywheel housing 100 of this embodiment is equipped with a drainage mechanism for draining such water.

[0050] Figure 5 is a perspective view (part 1) illustrating a part of the main body. Figure 5 shows a perspective view of the lower part of the main body 110 on the X1 side, viewed from diagonally upwards. Figure 6 is a perspective view (part 2) illustrating a part of the main body. Figure 6 shows a perspective view of the lower part of the main body 110 on the X2 side, viewed from diagonally downwards.

[0051] In the flywheel housing 100, a first through-hole 117 is provided in the lower part of the housing portion 111 of the main body portion 110. The first through-hole 117 is provided so as to open downwards at the lowest position in the bowl-shaped housing portion 111 of the main body portion 110. The provision of the first through-hole 117 in the main body portion 110 allows water to be discharged from the housing portion 111 to the outside through the first through-hole 117.

[0052] A stepped portion 118 is provided on the inner circumferential surface 111a of the housing portion 111 in the main body 110. The stepped portion 118 is connected to a first through hole 117. That is, the first through hole 117 is located in the middle of the stepped portion 118 which is provided continuously in the circumferential direction. By providing the stepped portion 118, water adhering to the inner circumferential surface 111a of the housing portion 111 is guided along the stepped portion 118 to the lower part of the inner circumferential surface 111a. The water guided to the lower part of the inner circumferential surface 111a is then discharged to the outside of the main body 110 through the first through hole 117 which is connected to the stepped portion 118. By providing the stepped portion 118, the water in the housing portion 111 is guided along the stepped portion 118 along the inner circumferential surface 111a and efficiently led to the first through hole 117 and discharged to the outside.

[0053] Figure 7 is a perspective view illustrating a part of the cover. Figure 7 shows a perspective view of the cover 120 with the X2 side facing X1. In the flywheel housing 100, a second through-hole 127 is provided in the inner circumference 122 located below the opening 125 of the cover portion 120. The second through-hole 127 is provided, for example, between the outer circumference 121 and the inner circumference 122 of the cover portion 120, penetrating from the back surface (X1 side) to the front surface (X2 side) of the cover portion 120. By providing the second through-hole 127 at the bottom of the cover portion 120, water can be discharged from the housing portion 111 to the outside through the second through-hole 127.

[0054] Figure 8 is a cross-sectional view illustrating a portion of the flywheel housing. Figure 8 shows a cross-sectional view of the lower part of the flywheel housing (viewed in the Y2 direction). When the flywheel 20 is housed in the housing section 111 and the cover section 120 is attached to the main body section 110, the protrusion 122a of the cover section 120 engages with the inner circumferential surface 111a of the main body section 110, and the cover section is attached with the center position aligned.

[0055] A groove 119 is provided in the circumferential direction on the inner circumferential surface 111a of the main body 110. In this embodiment, the groove 119 is formed between the wall portion 119a provided in the circumferential direction on the inner circumferential surface 111a of the main body 110 and the protrusion portion 122a of the cover portion 120. That is, the groove 119 is formed by attaching the cover portion 120 to the main body 110. The groove 119 is connected to the second through hole 127 of the cover portion 120. As a result, water in the housing portion 111 enters the groove 119 and is guided to the second through hole 127, allowing the water to be efficiently discharged from the second through hole 127.

[0056] Furthermore, a tapered portion 119b may be provided between the groove 119 and the second through-hole 127. The provision of the tapered portion 119b makes it easier for water guided by the groove 119 to flow through the tapered portion 119b into the second through-hole 127.

[0057] Preferably, the second through-hole 127 has a gradually increasing portion 127a in which the inner diameter gradually increases toward the surface of the cover portion 120 (from the X1 side to the X2 side). The gradually increasing portion 127a may be such that the inner diameter of the second through-hole 127 expands in steps or expands continuously. Furthermore, the gradually increasing portion 127a may be provided so that the inner diameter expands symmetrically with respect to the central axis of the second through-hole 127 or expands asymmetrically. For example, the lower side (Z2 side) of the inner diameter of the second through-hole 127 may expand more than the upper side (Z1 side). This makes it easier for water guided into the second through-hole 127 to flow in the direction of discharge through the gradually increasing portion 127a, and suppresses backflow of water.

[0058] (Structure of the support structure) Next, the structure of the support portion of the flywheel housing 100 will be described. Figure 9 is a perspective view illustrating a support portion provided on the flywheel housing. Figure 10 is a side view illustrating a support portion provided on the flywheel housing. Figure 10 also shows a side view of the upper part of the flywheel housing. In the flywheel housing 100 according to this embodiment, a support portion 130 for supporting other members is provided on the upper part of the main body portion 110. Examples of other members supported by the support portion 130 include vibration suppression devices for the engine 1 (vibration dampers, auxiliary bars, etc.).

[0059] The support portion 130 has a base portion 131 that extends upward (towards Z1) from the upper part of the main body portion 110, and a pedestal portion 132 that is provided on the base portion 131. The upper surface of the pedestal portion 132 is a flat pedestal surface 132b, and for example, screw holes 132c are provided. Other members are fixed to the support portion 130 using these screw holes 132c.

[0060] The base portion 132 is provided on the foundation portion 131 so as to extend toward the side of the cover portion 120 (X2 side) while avoiding the cover portion 120. That is, the foundation portion 131 of the support portion 130 is provided facing upwards toward the main body portion 110, but the base portion 132 is provided extending outwards from above the main body portion 110 toward the side of the cover portion 120. This makes it possible to secure a sufficient area of ​​the base surface 132b (base region) while avoiding interference between the support portion 130 and the cover portion 120.

[0061] The tip 132a of the base portion 132 in the extending direction is located on the side of the surface 120a of the cover portion 120 (X2 side) than the joint surface 135 between the main body portion 110 and the cover portion 120, and on the side of the main body portion (X1 side) than the surface 120a of the cover portion 120 (see range L shown in Figure 10). As a result, the base portion 132 does not protrude beyond the surface 120a of the cover portion 120 on the X2 side, and a sufficient base area can be secured.

[0062] The support portion 130 preferably has reinforcing ribs 133 connected to at least the base portion 131. In this embodiment, the reinforcing ribs 133 are provided between the X1 side surface of the base portion 131 and the main body portion 110. This reinforces the strength of the base portion 131.

[0063] Furthermore, when viewed from above the engine 1, it is preferable that the engine 1 and the components connected to the engine 1 are not positioned to overlap with the upper surface (base surface 132b) of the base portion 132. By not positioning the engine 1 or the components connected to the engine 1 above the base portion 132, the degree of freedom in the connection positions of other components attached to the base portion 132 is increased.

[0064] As an example, the cylinder head 3 of engine 1 is provided with a lifting hook 31 (see Figure 1) used when lifting engine 1. When viewed from above engine 1, the base portion 132 is positioned at a distance from the lifting hook 31 connected to engine 1. This prevents the base portion 132 from getting in the way when lifting engine 1 by attaching a lifting member to the lifting hook 31. In addition, the reinforcing rib 133 is inclined in a direction away from the lifting hook 31 (i.e., in the direction of X2) as it moves from the base portion 131 towards the base portion 132 (i.e., from the Z2 side towards the Z1 side). This prevents the reinforcing rib 133 from getting in the way when lifting engine 1 by attaching a lifting member to the lifting hook 31. It is preferable not to place engine 1 or members connected to engine 1 above the base portion 132, even if there is no lifting hook 31.

[0065] The support portion 130 may be provided as one on the main body portion 110, or there may be two or more. For example, if two support portions 130 are provided, it is preferable that the two support portions 130 are provided in symmetrical positions with respect to the crankshaft 9, which is the output shaft, when viewed from above the engine 1. By providing the two support portions 130 in symmetrical positions with respect to the crankshaft 9, vibration damping devices can be attached to these support portions 130 to effectively suppress vibrations around the crankshaft 9 of the engine 1 (vibrations in the rotational direction centered on the crankshaft 9).

[0066] Furthermore, if, for example, one support portion 130 is provided, it is preferable to position the support portion 130 so that it overlaps with the crankshaft 9 when viewed from above the engine 1. This effectively suppresses vibrations around the crankshaft 9 of the engine 1 (vibrations in the rotational direction centered on the crankshaft 9), similar to the above.

[0067] According to this embodiment, it is possible to provide a flywheel housing 100 and an engine 1 equipped with the flywheel housing 100 that can suppress the increase in size of the engine 1 and improve workability.

[0068] Embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the claims. The configurations of the above embodiments can be partially omitted or combined in any way different from those described above. [Explanation of Symbols]

[0069] 1…Engine, 2…Cylinder block, 3…Cylinder head, 4…Head cover, 5…Cylinder, 6…Crankcase, 7…Oil pan, 9…Crankshaft, 10…Blow-by gas treatment device, 20…Flywheel, 31…Lifting hook, 100…Flywheel housing, 110…Main body, 111…Housing section, 111a…Inner circumferential surface, 115…Hole, 117…First through hole, 118…Stepped section, 119…Groove section, 119a…Wall section, 119b…Tapered section, 120…Cover Part, 120a...Surface, 121...Outer circumference, 122...Inner circumference, 122a...Convex part, 122b...Opposite surface, 123...Concave, 123b...Bottom surface, 123c...Curved surface, 123d...Curved surface, 123s...Side surface, 124...Rib, 124a...Tip, 125...Opening, 125a...Edge, 126...Mounting hole, 127...Second through hole, 127a...Gradual increase part, 130...Support part, 131...Base part, 132...Base part, 132a...Tip, 132b...Base surface, 132c...Screw hole, 133...Reinforcing rib, 135...Joint surface

Claims

1. A flywheel housing that accommodates a flywheel connected to the output shaft of an engine, The flywheel is positioned on the engine side and has a main body having a housing portion for housing the flywheel, A cover portion is positioned on the opposite side of the flywheel from the engine, connected to the main body, and having an opening with an inner diameter smaller than the outer diameter of the flywheel. Equipped with, The cover portion is provided with a recess on the surface facing the flywheel at the periphery of the edge of the opening, which is concave in a direction away from the flywheel. A flywheel housing characterized by having a curved surface between adjacent sides of the aforementioned recesses.

2. A flywheel housing that accommodates a flywheel connected to the output shaft of an engine, The flywheel is positioned on the engine side and has a main body having a housing portion for housing the flywheel, A cover portion is positioned on the opposite side of the flywheel from the engine, connected to the main body, and having an opening with an inner diameter smaller than the outer diameter of the flywheel. Equipped with, The cover portion is provided with a recess on the surface facing the flywheel at the periphery of the edge of the opening, which is concave in a direction away from the flywheel. The opposing surface is provided with a plurality of recesses on the circumference around the opening, and ribs are provided between adjacent recesses. A flywheel housing characterized in that the space between the outer surface of the rib and the bottom surface of the recess is curved.

3. The flywheel housing according to claim 1 or 2, characterized in that the edge of the opening is located on the bottom surface of the recess.

4. The flywheel housing according to claim 1 or 2, characterized in that a curved surface is provided between the side surface and the bottom surface of the recess.

5. The flywheel housing according to claim 1, characterized in that a plurality of recesses are provided on the opposing surface on the circumference around the opening, and ribs are provided between adjacent plurality of recesses.

6. The flywheel housing according to claim 5, characterized in that the space between the outer surface of the rib and the bottom surface of the recess is curved.

7. The flywheel housing according to claim 2 or 5, characterized in that the tip of the rib in the extending direction is located at the edge of the opening.

8. The flywheel housing according to claim 2 or 5, characterized in that the width of the rib narrows in the direction of extension.

9. An engine comprising a flywheel housing that accommodates a flywheel connected to the output shaft of the engine, The flywheel housing is The flywheel is positioned on the engine side and has a main body having a housing portion for housing the flywheel, A cover portion is positioned on the opposite side of the flywheel from the engine, connected to the main body, and having an opening with an inner diameter smaller than the outer diameter of the flywheel. Equipped with, The cover portion is provided with a recess on the surface facing the flywheel at the periphery of the edge of the opening, which is concave in a direction away from the flywheel. An engine characterized by having a curved surface between adjacent sides of the aforementioned recess.

10. An engine comprising a flywheel housing that accommodates a flywheel connected to the output shaft of the engine, The flywheel housing is The flywheel is positioned on the engine side and has a main body having a housing portion for housing the flywheel, A cover portion is positioned on the opposite side of the flywheel from the engine, connected to the main body, and having an opening with an inner diameter smaller than the outer diameter of the flywheel. Equipped with, The cover portion is provided with a recess on the surface facing the flywheel at the periphery of the edge of the opening, which is concave in a direction away from the flywheel. The opposing surface is provided with a plurality of recesses on the circumference around the opening, and ribs are provided between adjacent recesses. An engine characterized in that the space between the outer surface of the rib and the bottom surface of the recess is curved.

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