JPS6383462A - Transfer case - Google Patents

Abstract

PURPOSE:To prevent noise due to film vibration by placing opposite the forward ends of ribs projected on the inner surface of a case member to increase the surface rigidity. CONSTITUTION:Ribs 43, 44 and 45, 46 are brought into contact with each other to form partition walls, so that an oil path 47 is formed on the outer peripheral side of a drive sprocket 18. Among the respective opposite surfaces of a front case 13 and a rear case 15, the portions positioned between the sprockets 18, 19 are provided with oil receiving ribs 48, 49 projected thereon, the forward ends of which are brought into contact with each other. Though vibration is caused by operation of a power transmission mechanism 20 in the driving condition, the oil receiving ribs 48, 49 placed opposite each other are formed on the inner surfaces of the front case 13 and the rear case 15 forming a chain room 14 to increase the surface rigidity. Accordingly, film vibration in the chain room 14 can be restrained to effectively prevent generation of noise.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a case of J. Ransuf 7 that distributes driving force between rear wheels and front wheels in a four-wheel drive system, for example.
In particular, winding of a chain transmission mechanism, etc. is necessary in connection with a case that houses the transmission mechanism.

Conventional technology Four-wheel drive (transfer) is used to distribute the driving force given by the transmission between the front wheels and the rear wheels, and as a transmission mechanism in this transfer, space and Chain transmission II for Ig sound reasons
I is sometimes used.

This transmission mechanism is naturally housed in the transfer case like other parts, but the storage chamber that houses the transmission mechanism, or the chain seedling, is a fairly large cavity compared to other parts, so the chain The wall surface of the case that forms the II! causes so-called membrane vibration, which causes noise. Efforts are made to prevent vibration.

In addition, the chain is generally lubricated by forming an oil sump within the chain and performing splash lubrication using the driving force of the chain, but if there is a lot of lubricant loss in the sump, In this case, the agitation of the lubricating oil becomes excessive, causing problems such as an increase in oil temperature and loss of power. Therefore, the present applicant proposed a lubricating device in Japanese Patent Laid-Open No. 60-234173, in which an oil reservoir having an outlet is provided between each sprocket on the inner peripheral side of the back chain.

Problems to be Solved by the Invention However, four-wheel drive transfers require extremely limited space due to requirements such as ensuring the minimum ground clearance of the vehicle above a certain height and widening the entire interior space to a certain extent. Therefore, when providing ribs on the outer surface of the case, there are restrictions due to interference with the rear engine mount, etc., and it has been difficult to provide effective ribs with necessary and sufficient rigidity.

On the other hand, regarding lubrication within the case, the degree of aη lubricating oil agitation in the oil sump can be reduced by the aforementioned lubrication device proposed by the present applicant. However, a considerable amount of lubricating oil flows back inside the case as it travels along the inner surface of the case.In contrast, the lubricating device proposed by the applicant mentioned above has an oil receiver that is separate from the case. Because it is partially separated from the inside of the case,
Lubricating oil cannot be stored effectively in the secondary oil reservoir,
There is also the problem of increased costs due to increased man-hours for manufacturing and assembly. Furthermore, since the secondary oil reservoir is formed by attaching an oil receiver that is separate from the case, there is almost no reinforcing effect or rib effect on the case, and as a result, the ribs on the outer surface of the case Since it is not useful for reducing ff1ffi, there is a problem that it causes an increase in ff1ffi.

This invention was made against the background of the above-mentioned circumstances, and it is an object of the present invention to provide a 1-heran SF 7 case with small external dimensions, high surface rigidity, and excellent lubricity for internal equipment.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a first recess provided with recesses that are joined to each other to form the above-mentioned receiving space.
It consists of a case member and a second case member, and on at least one of the mutually opposing surfaces of these case members, between each rotary body in the transmission mechanism facing the accommodation chamber and on the inner peripheral side of the transmission medium. A case in which a rib is provided so as to protrude so that the rib is positioned, the rib is shaped to have a concave cross-section that is concave downward, a penetrating portion that penetrates downward is formed in the concave cross-section, and the tips of the rib are opposed to each other. It is characterized by abutment against the inner surface of the member or a rib protruding from the inner surface.

Function: The rib in the present invention is provided to protrude from the inner surface of at least one of the first case member and the second case member, and the tip of the rib is butted against the inner surface of the other case member or the rib protruded from the inner surface of the other case member. The ribs increase surface rigidity.

In addition, since the rib has a concave cross-section, lubricating oil accumulates there, and since the rib protrudes from the inner surface of the case member, the lubricating oil flowing along the inner surface of the case can be effectively absorbed. can be stored in Furthermore, since the lubricating oil accumulated on the ribs drips through the through-hole onto the transmission medium and the rotating body around which it is wound, effective lubrication is achieved and less lubricating oil is stirred.

Embodiments Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 1 shows four-wheel drive 1 to Lancer 1 to which this invention is applied.
FIG. 2 shows a drive power transmission system of a front engine rear wheel drive type (FR vehicle) incorporating the transfer 1. In other words, in FIG. 2, an automatic transmission 2 mainly includes a torque converter and a plurality of planetary gear mechanisms.
is arranged on the rear side of the engine 3, and the transmission gear 71 is connected to the rear end side of the automatic transmission 2, and the transmission output lNI4 serves as the input shaft of the transfer 1. The transfer 1 is configured to distribute driving force between the rear wheels and the front wheels via a center differential device 6 whose differential operation is limited by a differential control clutch 5 that is slip-controlled. The rear export force shaft 7 in the transfer 1 is the transmission output shaft 4
A companion 7 is disposed on the same axis as the rear propeller shaft, and a companion 7 is provided at the tip of the companion 7 to connect the rear propeller shaft (not shown).
Runci 8 is installed. On the other hand, the front export force axis 9
is arranged parallel to the transmission output shaft 4, and the front propeller shaft 1Q is connected to this front export force 1TIllI9, and the front propeller! N110 is connected to the pinion drive shaft 12 of the front differential device 11.

As shown in Fig. 1, the case for collecting the functional parts of the transfer 1 is used to collect the front case 1 to case 13 that are connected to the case of the automatic transmission 2, and the case that is attached to the front case 13 and connects the chain together with the front case 13. 14 and housing the differential control clutch 5 and center differential device 6;
Extension housing 16 connected to the rear part of 5
It is composed of. The opposing portions of the front case 13 and the rear case 15 are somewhat recessed in opposite directions in the axial direction of the transmission output shaft 4, and the recessed portions correspond to 1 Herans transmission output l1II! 14 protrudes in the radial direction. Therefore, by connecting the front 1 to the case 13 and the rear case 15 in a careless manner, a chain toe 14 is formed by each recess, and a silent chain is inserted into the chain toe 14. 17, and a transmission groove 20 consisting of a drive sprocket 1B and one driven sprocket around which the drive sprocket 1B is wound.

The drive sprocket 18 has an insertion hole 21 formed along its central axis, and has a boss that is short at the front side (left side in Figure 1) and long at the rear side (right side in Figure 1). It is rotatably held relative to the front case 13 and rear case 15 by a pair of bearings 22 and 23 fitted into the outer periphery of the boss portion. The transmission output shaft 4 is inserted into the insertion hole 21 of the drive sprocket 18 in a non-contact manner, so that the two are arranged concentrically with each other.

The driven sprocket 19 also has an insertion hole 24 formed along its central axis, and bearings 25 and 26 fitted to boss portions on both front and rear sides sandwiching the sprocket allow the front case 13 and rear case 15, which is rotatably held at a portion that protrudes in the radial direction.

In this state, the driven sprocket 19 is parallel to the drive sprocket 18, and the rear end (right side in FIG. 1) is located inside the rear case 15, whereas the front end (left side in FIG. 1) is open to the front side together with the front case 13. and silent chain 1
7 is wrapped around these sprockets 1 to 18 and 19.

The rear drive sprockets i to 18 of the transmission mechanism 20 configured in this manner are formed with an oil hole 27 that opens at the bottom of one of the teeth in the garden portion and the inner surface of the insertion hole 21. A groove 28 extending in the circumferential direction is formed at the opening of the curved hole 27 on the inner peripheral surface of the groove 21 . On the other hand, in the transmission output shaft 4, a lubricating oil passage 29 that communicates with a hydraulic power source (not shown) such as an oil pump provided in the automatic transmission 2 is formed along the central axis up to the tip.
A sprocket oil hole 30 extending from a lubricating oil passage 29 to the outer periphery is formed in a portion of the transmission output shaft 4 that corresponds to the above-mentioned groove 28 in a radial direction. That is, the oil pumped from the hydraulic power source of the automatic transmission 2 is transferred to the lubricating oil passage 29 and the sprocket oil hole 30.
The oil is also supplied to the teeth of the drive sprocket 18 through the oil hole 27.

Furthermore, the front boss part of the drive sprocket 18 is set to have a length that is almost the same as the width of the bearing 22, and the bearing oil hole 31 opens at a position slightly removed from the tip of the boss part. Similar to the sprocket oil hole 30,
It is formed in the radial direction of the transmission output N14.

An oil kite 32 is provided inside the front case 13 to guide oil ejected from the bearing oil hole 31 to the bearing 22. That is, the oil guide 32 is an original portion with a diameter slightly larger than the outer diameter of the transmission output 11iIII4, and is integrally formed so as to extend forward from the portion of the front case 13 that holds the outer race of the bearing 22. As shown in FIG. 3, its tip (inner peripheral edge) is located forward of the opening of the bearing oil hole 31 so as to cover the opening. Furthermore, the inner surface of the oil guide 32 is configured such that, for example, the inner surface of the oil guide 32 has a radius of
The guide 33 is inclined at 5 degrees.

On the other hand, the driven sprocket 19 constituting the transmission Ia structure 20 is provided with means for preventing oil leakage. That is, an oil seal 34 is fitted into the outer periphery of the front boss portion, and a plug 35 is fitted at the end located inside the rear case 15 behind the insertion hole 24, and a seal is provided between the oil seal 34 and the plug 35. An oil seal 36 is fitted.

This plug 35 and oil seal 36 are connected to the front export force shaft 9
This is to prevent oil from flowing into the insertion hole 24 before the front export force shaft 9 is fitted into the insertion hole 24, and to bleed air when the front export force shaft 9 is inserted.The details are shown in Fig. 4. be. That is, the plug 35 consists of a short shaft portion 37 with a diameter smaller than the inner diameter of the insertion hole 24 and a length of 1TlllI, and a flange portion 38 that tightly fits into the inner peripheral surface of the open end of the insertion hole 24. 38 has a slit portion 39 formed by cutting out a part, and the slit portion 3
9 allows communication between the inside and outside of the insertion hole 24. Further, the oil seal 36 is connected to the shaft portion 37 and the insertion hole 24.
The lip portion 40 is disposed between the inner circumferential surface of the shaft portion 37 and the lip portion 40 protrudes toward the inner circumferential side, and is in contact with the outer circumferential surface of the shaft portion 37 . This lip portion 40 can be bent due to the pressure difference between the inner and outer sides of the insertion hole 24, and therefore the lip portion 40 substantially functions as a valve.

The front export force shaft 9 is inserted from the front side into the insertion hole 24 of the driven sprocket 19 configured in this way and is spline-fitted, and this front export force lNl9 and the insertion hole 24
A seal is provided between the inner circumferential surface and the inner circumferential surface of the ring 41 by a ring 41. A front propeller shaft 10 is connected to the front end of the front export force shaft 9 via a joint portion 42 such as a universal joint.

Next, the configuration for circulating oil within the chain 14 will be explained. As mentioned above, the transmission h'L2
The rear case 15 is provided with strong lubrication from the drive sprocket 18, so an oil discharge port 15a is formed in the rear case 15 for returning oil to an external oil sump (not shown) such as an oil pan. In other words, as shown in FIG. 5, the carrier case 15 is viewed from the rear of the vehicle, and the driven sprocket 19
are arranged diagonally below, and arc-shaped ribs 43, 44, 45, 46 located above and on the sides of the drive sprockets 1 to 1ε3, respectively, are located opposite to each other in the front case 13 and the rear case 15. It is protruded from the surface. These ribs 43 , 44 and 45 , 46 abut each other to form a partition wall, and as a result, an oil passage 47 is formed on the outer peripheral side of the drive sprocket 18 . The oil discharge port 15a is provided at a position where oil drips from the oil passage 47.

Further, on the opposing surfaces of the front case 13 and the rear case 14, a rib 48. is located between each sprocket 18.
49 is provided protrudingly. These oil pans have ribs 48.49
As shown in Fig. 5, the receiver, which is directed upward while avoiding interference with the transmission collapse 20, etc., has a concave cross-sectional portion that is recessed downward to form a surface. A chain lubrication hole 50 is formed in the center as a penetrating portion for allowing oil to drip into the four "irent chains 17,"
The silent chain 17 is lubricated. Further, an oil seal: lubrication hole 51 is formed as another penetrating portion at an odd predetermined location on the inner wall surface of the chain 14 of the oil pan 748. The oil seal lubrication hole 51 is arranged in the front case 1 so as to reach the oil seal 34 arranged on the outer periphery of the boss portion of one driven sprocket.
It communicates with an oil passage 52 formed in 3.

The rear export force 1NI7 is rotatably supported by a pair of bearings 53 and 54 inside the extension housing 16 attached to the rear side of the rear case 15, and a gear 55 for vehicle speed adjustment is located in the middle of the extension housing 16. is attached, and a companion flange 8 is spline-fitted to the rear end of the rear export force 1ViilI7. An oil seal 56 seals between the companion flange 8 and the extension housing 16, and an O-ring 57 seals between the rear export force shaft 7 and the companion flange 8. And transmission output 11i! 4 is supported inside the base end (left end in FIG. 1) of the rear export force shaft 7 via a bearing 58.

A center differential device 6 that distributes the driving force of this transmission output IN4 between the rear wheels and the front wheels.
The differential control clutch 5 that performs the differential restriction is configured as follows.

The center differential device @ 6 is composed of a planetary tooth @ mechanism, and the gear 1 gear 59 that holds the planetary pinion is spline-fitted to the end of the transmission output shaft 4, while the ring gear 60 is connected to the rear export force shaft 7.
are connected and integrated.

On the other hand, the sun gear 61 is connected to the drive sprocket 1.
The support 6 has a cylindrical portion that is spline-fitted to the extension of the boss portion at 8 and extends toward the front side of the single image (left side in FIG. 1), and the cylindrical portion is fixed within the rear case 15.
It is rotatably fitted into the boss part of 2. Further, the differential braking clutch 5 is composed of a wet multi-disc clutch,
The clutch drum 63 is connected and integrated with a cylindrical portion of the sun gear 61 extending toward the support 62 side.
Furthermore, the clutch hub 64 is integrated with the ring gear 60 of the center differential device 6.

A cylinder is formed by the cylindrical portion of the sun gear 61 extending toward the rib 1-62 side and the clutch drum 63, and two large and small pistons are built in the cylinder in series, and the differential control clutch 5 is connected to the cylinder. A hydraulic servo a@65 is configured to operate the. This hydraulic servo special 65 engages the stop control clutch 5 by a piston moving against a return spring 66, and is controlled by a hydraulic control device 67 disposed below the rear case 15. It has become.

In the example shown in FIG. 1, the differential control clutch 5 is always engaged with a certain degree of engagement force to limit the differential of the center differential device 6, and the 1 to silk distribution to the rear wheel side is control so that the ratio increases.

In addition, transmission output! 114 is provided with oil holes extending from the lubricating oil passage 29 to the outer peripheral surface at necessary locations, and the sun gear 61 of the center differential device 6 has oil holes extending from the inner peripheral surface to supply oil to the tooth surfaces. It is formed from the surface toward the bottom of the tooth. Furthermore, the rear export force axis 7
A lubricating oil passage along the central axis is formed over a predetermined length from the base end thereof, and oil holes extending from the lubricating oil passage to the outer peripheral surface are formed at necessary locations.

In the four-wheel drive transfer 1 above, the transmission output! '1114 gives driving force to the carrier 59 of the center differential device 6, and the driving force is transmitted from the ring gear 60 to the rear export force shaft 7, and from the sun gear 61 to the drive sprocket 18.

In that case, the differential control clutch 5 is controlled to slip and the differential operation of the center differential device @ 6 is limited to some extent, so that the torque distribution ratio between the rear export power shaft 7 and the drive sprocket 18 is 50:50. It varies depending on the degree of differential restriction. The driving force given to the drive sprocket 18 is silent chain 1
7 and the driven sprocket 1-19 to the front export force shaft 9, and further to the front propeller 1Fll110 connected at the joint portion 42. In other words, a four-wheel drive state is created in which the torque distribution ratios to the front and rear wheels are different.

In such a driving state, vibrations occur due to the operation of the transmission groove 20, but there are ribs 48, 49 on the inner surfaces of the front case 3 and the gloss case 15 that form the chain to 14, and the sacrum that butts against each other. Since the surface 11i111 is formed and the surface 11i111 property is high, the chain to 1
The vague vibration at 4 is suppressed by 1%! Generation of sound is effectively prevented.

In addition, when the transmission mechanism 20 is in operation, oil is pumped from the oil pressure source of the automatic transmission 2 through the lubricating oil passage 29 formed in the i-transmission output shaft 4, but a portion of the oil is fed through the sprocket oil hole. 30 to drive sprocket 18
is supplied to the inner peripheral surface side. A recess 28 is formed on the inner surface of the drive sprocket 18 along the circumferential direction, and the sprocket oil hole 30 is located in line with the groove 2B, and since the drive sprocket 18 is rotating, the oil is The oil is held inside the groove 2B by centrifugal force, and is sequentially supplied to the groove from the oil hole 27 extending from the groove 28 to the bottom of the tooth. That is, the drive sprocket 18 is forcibly lubricated by the hydraulic power source in the automatic transmission 2. Also, the rotation speed of the drive sprocket (~18) and the rotation speed of the transmission output shaft 4 are the center differential V
As a result, the front end of the sprocket oil hole 30 and the front end of the oil hole 27 formed in the drive sprocket 18 do not necessarily match, but the oil Since it is held by the groove 28, oil is reliably supplied to the teeth of the drive sprocket 18.

On the other hand, the silent chain 17 is lubricated not only by being supplied with oil from the drive sprocket 18 but also by splashing some of the oil that has accumulated inside the chain 14. The oil adhering to the silent chain 17 is carried by the running of the chain 17, and a part of it falls while the silent chain 17 is running. The oil pan is located above the ribs 48, 49, and the oil separated from the Salent chain 17 is transferred directly or along the inner surface of the chain to the chain 14 to the top of the ribs 48, 49, as shown by the arrow in FIG. The ribs 48 and 49 of the oil sump flow in and accumulate, so that the ribs 48 and 49 essentially serve as secondary oil sumps. As described above, the oil sump 748.49 has the chain lubrication hole 50 and the oil seal lubrication hole 51 formed therein, so the oil in the auxiliary oil sump drips from the chain lubrication hole 50 onto the silent chain 17, and the oil also drips into the silent chain 17. The seal lubrication hole 51 reaches the oil seal 34 on the outer circumferential side of the driven sprocket 19, so that the silent chain 17 and the oil seal 3/1 are well lubricated. On the other hand, a sufficient amount of lubricant W (oil accumulates at the bottom of the chain holder 14, but a considerable portion of the total lubricating oil that collects at the bottom of the chain holder 14 in a stationary state accumulates in the aforementioned secondary oil sump in an operating state. , in the operating state, the amount of oil in the oil sump formed at the lower part of the chain toe 14 is reduced, in other words, there are fewer chains of oil available for splash lubrication H'J, and the oil level is lowered. The degree of oil agitation by the silent chain 17 is reduced, and inconveniences such as oil temperature rise and power loss are improved.

d3. The transmission groove targeted by this invention is not limited to the transmission mechanism where the chain is wound, and it goes without saying that the chain may be wound in the transmission groove.

Effects of the Invention As explained above, according to the transfer case of the present invention, a rib is provided protruding from the inner surface of the case member that forms the storage chamber for the chain holder, and the tip of the rib is connected to the other rib, etc. Since it is butted against the opposing portion, the surface rigidity of the portion forming the storage chamber is increased, and as a result, the ribs on the outer surface can be reduced and the outer diameter of the case as a whole can be reduced. In addition, the ribs inside the accommodation chamber essentially form a sub-oil sump, and the sub-oil sump is located on the inner circumference side of the transmission medium, so the level of oil scraped up by the transmission medium is This reduces oil temperature rise and power loss due to agitation more than ever before, and at the same time allows lubricating oil to flow along the inner surface of the storage chamber into the secondary oil sump for effective lubrication. Since oil can be stored and the lubricating oil drips onto the transmission mechanism such as the transmission medium through the penetration part, effective lubrication can be achieved. Furthermore, since the ribs on the outer surface, which were conventionally provided, can be eliminated, GM can be reduced, and since new parts are not installed, costs can also be reduced.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the transfer according to the present invention, Fig. 2 is a schematic diagram of the driving force transmission system, Fig. 3 is a partially enlarged view of the oil guide, Fig. 4 is the plug J-i and the oil seal. Fig. 5 is a partial view showing the beam A7 case as seen from the rear of the vehicle. 1... Four-wheel drive transfer, 13... Front case, 14... Chain to, 15... Rear case, 17... Silent chain, 18... Drive sprocket, 20... Transmission mechanism, 48.
49...Oil pan is rib, 50...Chain lubrication hole,
51...Oil seal lubrication hole.

Claims (1)

[Scope of Claims] In a transfer case provided with a housing chamber for housing a transmission mechanism consisting of a driving rotary body, a driven rotary body, and an endless transmission medium wound around these rotary bodies, the housing chamber is provided by being joined to each other. Consisting of a first case member and a second case member each having a recessed portion forming a chamber, at least one of the mutually opposing surfaces of these case members is provided with a portion between each of the rotating bodies and of the transmission medium. A rib is provided to protrude so as to be located on the inner circumferential side, and the rib has a concave cross-section concave downward, and a penetrating portion penetrating downward is formed in the concave cross-section, and the tips of the ribs are opposed to each other. A transfer case is characterized by being butted against the inner surface of the case member or a rib protruding from the inner surface.