JPH059557Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a balancer drive device in an engine with a secondary balancer.

[Prior Art] In Japanese Utility Model Publication No. 55-48724, a first timing belt device transmits the rotation of the crankshaft to the camshaft, and a second timing belt device is provided to transmit the rotation to the balancer shaft. An engine is disclosed that is equipped with an external gear type oil pump that is driven by the engine.

[Problems to be solved by the invention] As described above, in conventional engines with secondary balancers, two crank pulleys are provided, one for driving the cam and the other for driving the balancer, so in order to avoid increasing the overall length of the engine, oil The pump was an external gear type pump, which also served as a gear installed on the balancer shaft. Therefore, compared to an engine without a secondary balancer, which has an internal gear type oil pump directly connected to the crankshaft, the structure for driving the oil pump is more complex, and there are also problems such as the generation of noise peculiar to external gear type pumps. be. Furthermore, since two timing belts are attached to the crankshaft, there is a disadvantage that the load on both belts due to torsional vibration of the crank becomes large.

Therefore, the purpose of this invention is to provide an internal gear type pump that is directly connected to the crank, which has a simple drive structure for the oil pump and eliminates the risk of noise generation, in an engine equipped with a timing belt device for driving a cam and a timing belt device for driving a balancer. However, in order to shorten the overall length of the engine compared to an engine with a secondary balancer that drives the balancer with a chain,
There is no need to use a chain to drive the balancer and camshaft, which have problems with noise generation, and even compared to an engine without a secondary balancer, there is no need to change the crankshaft, that is, the overall length of the engine. Another object of the present invention is to provide an engine balancer drive device which eliminates the disadvantage of a large belt load due to torsional vibration of a crank.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides an engine balancer drive device in which an internal gear type oil pump 35 and a crank pulley 12 are connected to one end of the crankshaft 11 from the inside to the outside. in this order, and the first
It is characterized in that the second timing belt 30 is disposed inside the timing belt 10 and at a position where the oil pump 35 is surrounded by a tensioner 34.

[Function] Rotation of the crank pulley 12 is controlled via the first timing belt 10 to the cam pulleys 14 and 16 and the first sub-pulley 18 disposed on the tight side between the crank pulley 12 and the cam pulley 16.
The rotation of the first sub-pulley 18 is transmitted to the first balancer shaft 23 via the first gear mechanisms 24 and 25, and the rotation of the first sub-pulley 18 is transmitted to the first balancer shaft 23, which is attached to the first balancer shaft 23.
3 to the second sub-pulley 32 via the second timing belt 30, and the rotation of the second sub-pulley 32 to the second balancer shaft 21 via the second gear mechanism 22, 26. , the first and second balancer shafts 23 and 21 are driven in synchronization with the crankshaft 11.

[Example] Examples will be described below based on the accompanying drawings.

FIG. 1 is a schematic front view showing the balancer drive device of the present invention. In the drawing, 1 is an in-line four-cylinder DOHC engine, and cylinder block 2
A cylinder head 3 is connected to the top, an oil pan 4 is connected to the bottom of the cylinder block 2, and a cylinder head 3 is connected to the bottom of the cylinder block 2.
A head cover 5 is attached on top of each.

10 is a first timing belt, 11 is a crankshaft, and 13 and 15 are a pair of camshafts.
A crank pulley 12 and cam pulleys 14 and 16 are provided at each end. Further, a water pump pulley 17 is arranged below the right cam pulley 14, a first sub-pulley 18 is arranged below the left cam pulley 16, and a tensioner pulley 19 above the crank pulley 12 is arranged below the right cam pulley 14. It is located.

Each of the above pulleys 12, 14, 16, 17, 1
A toothed timing belt (first timing belt) 10 is attached to the first sub-pulley 18 and the tensioner pulley 19, and the first timing belt 10 is in pressure contact with the first sub-pulley 18 and the tensioner pulley 19, and the inner circumferential surface of the first timing belt 10 is in pressure contact with the other pulleys. They are engaged on the circumferential surface. The camshafts 13 and 15 are driven at a speed of 1/2 of the rotation of the crankshaft 11 by this first timing belt device.

Next, the balancer drive device will be explained.

That is, in the figure, 21 and 23 are a pair of balancer shafts (23 is called a first balancer shaft, 21 is called a second balancer shaft), and these balancer shafts 21 and 23 are connected to the water pump pulley 17 and the first sub-pulley 18. Driven gears 22 and 24 are provided at each end that is disposed below and protrudes from the end face of the engine, respectively.

Both driven gears 22 and 24 are located further inward than the first timing belt device,
A drive gear 25 that directly meshes with the left driven gear 24 is provided integrally with the shaft 20 of the first sub-pulley 18 . In addition, the right driven gear 22 has a drive gear 2 arranged downward.
6 are directly engaged.

Further, the shaft 31 of the right drive gear 26 is integrally provided with a second sub-pulley 32 , and the first balancer shaft 23 on the left side is also integrally provided with a first balancer pulley 33 , which is located below the crank pulley 12 . A tensioner pulley 34 is arranged. These pulleys 32,
33, 34 are located further inward than the gears 22, 24, 25, 26, and each pulley 32,
A second toothed timing belt (second timing belt) 30 is hooked onto the inner circumferential surfaces of the belts 33 and 34 .

Both balancer shafts 21 and 23 are connected to the crankshaft 11 by the pair of left and right gear mechanisms and the second timing belt type balancer drive device.
It is driven at twice the speed of rotation.

Here, the rotation directions of the main pulley and each gear are shown by arrows in the figure, and both balancer shafts 21, 23 rotate in opposite directions.

In the above, the internal gear type oil pump 35, that is, the trochoid type oil pump 35 in the embodiment, is directly connected to the crankshaft 11 in the space surrounded by the second timing belt device for driving the balancer that extends left and right and downward. It is set up. In the drawings, the trochoid pump 35 is shown only as a housing, and its internal structure is omitted.

In addition, a timing belt cover (not shown) is attached to the end face of the engine 1, and at the tip of the crankshaft 11 protruding from the timing belt cover, other pulleys 36 and 37 that transmit driving force to the alternator and air conditioning compressor are installed as shown in Figure 2. Be prepared.

Note that the engine type is not limited to series or DOHC, but may also be parallel such as V type or SOHC. Further, the internal gear type oil pump is not limited to only the trochoidal tooth type pump, but also includes other tooth type pumps.

[Effects of the invention] As described above, according to the invention, since the first sub-pulley for driving the balancer is engaged with the tension side between the crank pulley and the cam pulley of the first timing belt, the rotation of the balancer is controlled by the crankshaft. The first balancer shaft is driven by a gear mechanism from the sub-pulley shaft, and the first balancer shaft is driven by a gear mechanism.
The second balancer shaft is reversely driven from the balancer shaft by a second timing belt device and a gear mechanism, and this balancer driving timing belt device equipped with a tensioner is directly connected to the crankshaft and surrounds an internal gear type oil pump. Due to its structure, only the crankshaft is equipped with a cam drive pulley.

Therefore, compared to an engine with a secondary balancer that drives the balancer with a chain, in order to shorten the overall length of the engine, there is no need to use a chain to drive the balancer and camshaft, which have problems with noise generation. Compared to an engine without one, there is no need to change the crankshaft, that is, there is no need to change the overall length of the engine. This makes it possible to use an internal gear type pump that is directly connected to the crank, which has the advantages of a simple oil pump drive structure and no worries about noise generation.
In addition, since the load of the balancer driving timing belt is not directly applied to the crankshaft, there is no longer a disadvantage that the belt load is large due to torsional vibration of the crank, which is the case when two belts are attached to the crankshaft.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view showing the balancer drive device of the present invention, and FIG. 2 is a partially cutaway side view of the oil pump portion. In the drawing, 1 is the engine, 10 is the first timing belt, 11 is the crankshaft, 12 is the crank pulley, 13 and 15 are the camshafts, 1
4 and 16 are cam pulleys, 17 is a water pump pulley, 18 is a first sub-pulley, 19 is a tensioner pulley, 20 is a sub-pulley shaft, 21 is a second balancer shaft, and 23 is a first
The balancer shaft 22, 26 is a driven gear and a drive gear 2 constituting the second gear mechanism.
4 and 25 are driven gears and drive gears that constitute the first gear mechanism, 30 is a second timing belt, 31 is a balancer pulley shaft, 32 is a second sub-pulley, 33 is a first balancer pulley, 34 is a tensioner pulley, 35 is an internal gear type oil pump.

Claims (1)

[Claims for Utility Model Registration] Rotation of the crank pulley 12 is controlled via the first timing belt 10 to the cam pulleys 14, 16 and a first sub-pulley disposed on the tight side between the crank pulley 12 and the cam pulley 16. 18
The rotation of the first sub-pulley 18 is transmitted to the first balancer shaft 23 via the first gear mechanisms 24 and 25, and the rotation of the first sub-pulley 18 is transmitted to the first balancer shaft 23, which is attached to the first balancer shaft 23.
3 to the second sub-pulley 32 via the second timing belt 30, and the rotation of the second sub-pulley 32 to the second balancer shaft 21 via the second gear mechanism 22, 26. , is a balancer driving device that drives the first and second balancer shafts 23 and 21 in synchronization with the crankshaft 11, and includes an internal gear type oil pump 35 and the crank pulley 1 at one end of the crankshaft 11.
2 are arranged in this order from the inside to the outside, and the second timing belt 30 is located inside the first timing belt 10 hooked on the crank pulley 12 and at a position surrounding the oil pump 35 by the tensioner 34. An engine balancer drive device characterized by the arrangement of.