JPH02245424A - Engine - Google Patents

Abstract

PURPOSE:To eliminate a special protection member for a sensor for detecting a crank angle by providing the sensor at a place opposite to a cover concealing the front of a lower case supporting a crankshaft and a rotary body fitted to the end of a crankshaft projected externally. CONSTITUTION:In a V-type engine having cylinder rows 4a and 4b erected in a V-form on the upper surface of a lower case 3 for supporting a crankshaft 2 drive pulley 28 is connected to the end of the crankshaft 2 led externally through a cover 15 concealing the front of the lower case 3. A ring-shape stepped part 35 is formed at the opposite surface 30a of a boss part 30 in the aforesaid pulley 28 to the cover 15, and a rotor 36 including a flange wall 39 with a partial notch 40 is fitted to the stepped part 35. On the other hand, a ring-shape groove 41 for housing the forward end of the flange wall 39 is formed at the surface of the cover 15 at a position opposite to the drive pulley 28. In addition, a recess part 42 formed at the intermediate part of the groove 41 is provided with a sensor 43 for detecting a crank angle from the position of the notch 40.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an engine in which a sensor for detecting a crank angle is provided around a crankshaft, and particularly to a structure around the sensor.

[Prior Art] For example, in an automobile engine, a sensor is placed around the crankshaft to detect the crank angle through a rotor that rotates together with the crankshaft, and ignition is performed based on the signal output from this sensor. The period is set.

On the other hand, in engines that transmit the rotation of the crankshaft to the camshaft via a timing belt, the timing belt is usually covered with a cover placed over the front surface of the cylinder block. In this type of engine, the present applicant has recently proposed accommodating the above-mentioned crank angle detection sensor in the space opened in the above-mentioned cover, and has already proposed it as "Japanese Patent Application No. 63-219496". The application has been completed.

This structure is possible because it does not require lubrication of the timing belt, but the following problems arise in engines that use a timing chain instead of the timing belt.

In other words, since the timing chain requires oil lubrication, oil is always supplied inside the cover. Therefore, if the sensor and rotor are housed inside the cover as in the prior art described above, oil will leak into the rotor. There is a risk of agitation and foaming, and the lead-out portion of the signal cable from the sensor to the ignition device must also be specially sealed. Therefore, in an engine in which a camshaft is driven by a timing chain, it is desirable to provide the rotor and sensor outside the cover.

[The problem WJ that the invention seeks to solve] However, if the rotor and sensors are exposed outside the cover, they will be more likely to be hit by flying stones or road protrusions while driving, increasing the risk of damage. is possible. Therefore, as a way to prevent this damage, the end of the crankshaft of an automobile engine usually passes through the cover, and a damper is attached to this end to prevent vibration of the crankshaft. It is conceivable to arrange the rotor and sensor in the space sandwiched between the damper and the cover.

However, since the space between the cover and the damper is not inherently that wide, in order to arrange the rotor and sensor in this space, the damper must be shifted toward the end of the crankshaft. As a result, the damper protrudes outward from the cover, resulting in a problem that the overall length of the engine increases accordingly.

The present invention was made based on these circumstances, and
To provide a compact and well-organized engine capable of preventing damage to a sensor and a rotor without providing a special protective member, and keeping the axial dimension of a crankshaft short.

[Means for Solving the Problem] Therefore, in the present invention, a sensor is provided around the crankshaft supported by the cylinder block to detect the crank angle through a rotor that rotates integrally with the crankshaft, and the above-mentioned A timing chain that transmits the rotation of the crankshaft to the camshaft is provided on one end of the crankshaft in the axial direction, and this timing chain is covered with a cover placed over the cylinder block, and the crank extends outward through the cover. In an engine in which a rotating body that rotates integrally with the crankshaft is attached to the end of the shaft, the rotor and sensor are placed in a space sandwiched between the cover and the rotating body, and the rotor and sensor are placed in a space between the cover and the rotating body. The device is characterized in that a recessed portion for accommodating at least the sensor is formed on the opposing surface.

[Operation 1] According to this configuration, the rotor and the sensor are covered by the cover and the rotating body from both sides in the axial direction of the crankshaft, and at least the sensor is inserted into the recess and is apparently embedded in the cover at the top. state, so these
The proportion of the sensor and rotor exposed to the outside is small. Therefore, the sensor and rotor can be protected from flying stones using the cover and the rotating body, eliminating the need for special protective members. Become.

Furthermore, since at least the sensor is inserted into the recess on the cover side, the rotating body can be brought closer to the cover side and the amount of outward protrusion can be kept to a minimum, reducing the dimension of the engine in the crankshaft direction. be able to.

[Embodiments] Hereinafter, embodiments of the present invention will be described based on drawings in which the present invention is applied to a V-type eight-cylinder engine.

The cylinder block indicated by the symbol l in the figure includes a lower case 3 that supports the crankshaft 2, and a V
It has a pair of cylinder rows 4a and 4b arranged vertically. The cylinder rows 4a and 4b have cylinder bodies 6a and 8b each having four cylinders 5 arranged in parallel in the axial direction of the crankshaft 2,
It is composed of cylinder heads 7a, 7b fitted onto these cylinder bodies 8a, 8b, and head forces t<-8a, 8b. The pistons of the cylinders 5 that face each other in a V-shape within the cylinder block 1 are connected to a common crank bin 2a on the crankshaft 2 via connecting rods, so that the pair of cylinder rows 4a and 4b are It is offset in the axial direction of the crankshaft 2.

In addition, the cylinder heads 7a, 7b and the head cover 8a,
8b accommodates an intake camshaft 10 and an exhaust camshaft 11.
A timing sprocket 12 is attached to one end.

One end of the crankshaft 2 passes through the front surface of the lower case 3 and at the same time passes through a cover 15 covering the front surface of the lower case 3 and is led out.
A sleeve 17 is fixed to the outer periphery of the crankshaft 2 that spans the lower case 3 and the lower case 3 via a key 16. A pair of drive sprockets 18a are provided on the outer periphery of this sleeve F.
, 18b are provided. driving sprocket 18a,
18b has the same number of teeth as the cylinder row 4a.
, 4b in the axial direction of the crankshaft 2 by an amount corresponding to the offset amount. In addition, lower case 3 and cover 15
There is an intermediate shaft 19a between each cylinder row 4a, 4b.
, 19b is supported. Intermediate shafts 19a, 19b
are located between the camshaft 10.11 and the crankshaft 2, and each has a first intermediate sprocket 20a on its outer periphery.
, 20b are supported. First intermediate sprocket 2
The number of teeth on the drive sprockets L8a and L&b on the crankshaft 2 is greater than the number of teeth on the drive sprockets 0a and 20b, and a single-stage timing chain 21 is installed between these two sprockets 18a and 18b and 20a and 20b. has been done. Therefore, the -th timing chain 21 is connected to the cover 1.
The timing chain 21 is housed inside the timing chain 5, and lubricating oil is supplied to the running path of the next timing chain 21.

Further, second intermediate sprockets 22a, 22b are provided on the intermediate shafts 19a, 19b, and the second intermediate sprockets 22a, 22b are integrated with the first intermediate sprockets 20a, 20b. The number of teeth of the second intermediate sprockets 22a, 22b is the timing sprocket 12, the driving sprocket 18a, 18b, and the first sprocket.
The number of teeth is smaller than that of the second intermediate sprockets 20a, 20b, and this second intermediate sprocket 22a,
A secondary timing chain 23 is mounted between the timing sprocket 22b and the timing sprocket 12. Therefore, the rotational speed of the crankshaft 2 is the same as that of the crankshaft 2 and the intermediate shaft 1.
9a, 19b and intermediate shafts 19a, 19b and camshaft 10
．． After being decelerated in two stages between camshaft 1 and
0.11.

On the other hand, a drive pulley 28 as a rotating body is attached to the shaft end of the crankshaft 2 that penetrates the cover 15 and is led out. A V-belt 25 that drives a water pump 26 and an alternator 27 is wound around this drive pulley 28 . As shown in FIG. 1, the drive pulley 28 includes a boss portion 30 fixed to the outer periphery of the shaft end of the crankshaft 2 via a key 29, and a ring-shaped belt wrapped around the outer periphery of the boss portion 80. Part 3! A belt groove 31a is formed on the outer circumferential surface of the belt wrapping portion 31, in which the V-belt 25 is wound. The belt wrapping portion 31 is a so-called vibration damping weight having a predetermined mass, and is supported in a floating state for vibration damping on the outer periphery of the boss portion 30 via an elastic body 32 made of rubber. has been done. Therefore, when the crankshaft 2 vibrates, the belt wrapping part 31 vibrates independently of the crankshaft 2, so this belt wrapping changes the natural frequency of the part 31 according to the natural frequency of the crankshaft 2. If set appropriately, it becomes possible to effectively offset the vibration of the crankshaft 2, and in the case of this embodiment, the drive pulley 28 also functions as a damper that prevents the vibration of the crankshaft 2.

Note that a boss portion 30 of the drive pulley 28 is located on the crankshaft 2.
A cylindrical spacer 33 is interposed between the sleeve 17 and the sleeve 17, and this spacer 33 penetrates the cover 15 via an oil seal 34.

By the way, such a driving pulley 28 is opposed to the cover 15, and a lower ring-shaped step part 35 is formed on a surface 30a of the boss part 30 facing the cover 15. Then, a rotor 3B of sheet metal type is attached to this stepped portion 3-5.
is installed. The rotor 3B has screws 3 on the stepped portion 35.
7, and a flange wall 39 extending from the outer periphery of the support part 38 toward the cover 15, and rotates together with the crankshaft 2. A notch 40 is provided in a portion of the flange wall 39 along the circumferential direction. Also, cover 1
The flange wall 3 is provided on the surface facing the drive pulley 28 of 5.
A ring-shaped groove 41 into which the tip of the ring 9 fits is formed, and a recess 42 recessed toward the lower case 3 is formed in the middle of this groove 41.
is formed. As shown in FIG. 2, the fourth part 42 is located above the crankshaft 2, and a sensor 43 is installed in the recess 42 to detect the crank angle of the crankshaft 2 from the position of the notch 40 of the rotor 36. is accommodated.

The sensor 43 includes a base 45 fixed to the bottom of the recess 42 via a bolt 44, and a detection section 4B supported by the base 45, and is located around the outer periphery of the crankshaft 2. Then, this detection section 4B and the base 45
The flange wall 39 of the rotor 36 is inserted into the gap 47 between the rotor 36 and the crank angle of the crankshaft 2 by detecting the notch 40 of the flange wall 39 with the detection section 4B. ing.

Therefore, the sensor 43 and rotor 3B have a force 1<
-15 and the drive pulley 28, and is covered by the cover 15 and the drive pulley 28 from both sides of the crankshaft 2 in the axial direction.

Furthermore, an insertion groove 50 that is continuous with the recess 42 is formed on the outer surface of the cover 15 . A signal cable 51 from the sensor 42 to an ignition device (not shown) is inserted into the insertion groove 50, and a retaining plate 52 that holds the signal cable 51 to prevent it from being pulled out is inserted into the opening of the insertion groove 50. It is stopped through.

According to such a configuration, since the sensor 43 for detecting the crank angle and the rotor 3B are arranged in the space 48 sandwiched between the drive pulley 28 located at the end of the crankshaft 2 and the cover 15, These sensors 43 and rotor 36 can be covered from both sides of the crankshaft 2 in the axial direction. Moreover, since the sensor 43 is accommodated in the recess 42 of the cover 15, it appears to be embedded in the upper part of the cover 15 side, and the proportion of these sensors 43 and rotor 38 exposed to the outside is reduced. . Therefore, the sensor 43 and the rotor 36 can be protected from flying stones and road surface protrusions without providing any special protection member.

Furthermore, since the sensor 43 is accommodated in the recess 42 of the cover 15, and the tip of the flange wall 39 of the rotor 3B also enters the groove 41 on the cover 15 side, the sensor 43 and the rotor 3B are covered accordingly. 15 side, the drive pulley 28 itself can be brought closer to the cover 15. Therefore, the space 48 becomes narrower, making it difficult for stones etc. to hit the sensor 43 and the rotor 3B, and the amount of protrusion of the drive pulley 28 relative to the cover 15 can be kept small, thereby reducing the dimensions of the engine in the crankshaft 2 direction. It can be shortened to create a compact engine.

In particular, as in this embodiment, the rotor 3B is connected to the drive pulley 28.
If the rotor 3B is attached to the boss 30 of the
Compared to the case where the drive pulley 28 is sandwiched between the rotor 3B and the spacer 33, the drive pulley 28 can be moved closer to the cover 15 by the thickness of the support portion 38 of the rotor 3B. As a result, the dimensions of the engine in two directions of the crankshaft can be reduced, which is advantageous in making the engine more compact.

In the above embodiment, the flange wall of the rotor is also inserted into the groove or recess of the cover, but the present invention is not limited to this.
Only the sensor may be housed in the recess, or the fuel injection timing may be determined based on the signal from this sensor.

Furthermore, in the above embodiment, the rotation of the crankshaft is once decelerated on the intermediate shaft and then transmitted to the camshaft, but it is also possible to omit this intermediate shaft and drive the camshaft with a single timing chain. good.

Furthermore, the engine according to the present invention is not limited to a V-type engine, and can be similarly implemented with, for example, an in-line multi-cylinder engine or a horizontally opposed engine.

[Effects of the Invention] According to the present invention described in detail above, the sensor for detecting the crank angle and the rotor can be protected from flying stones and road surface protrusions by using the cover and the rotating body. Moreover, the rotary body can be moved closer to the cover side by at least the amount that the sensor is embedded in the cover side, and the dimension of the engine in the crankshaft direction can be shortened, resulting in a compact and well-organized engine.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a sectional view showing the drive path around the crankshaft and the camshaft, FIG. 2 is a partially sectional front view of the camshaft drive path, and FIG. A front view of the cover, FIG. 4 is a sectional view taken along line ■-■ in FIG. 3, FIG. 5 is a sectional view taken along line V-V@ in FIG. 7, and FIG. 6 is a front view of the cylinder block. FIG. 7 is a front view of the entire engine, and FIG. 8 is a side view of the entire engine. l...Cylinder block, 2...Crankshaft, 10
．． 11...Camshaft (intake camshaft, exhaust camshaft),
15...Cover, 21...Timing chain (-
(Next timing chain), 28... Rotating body (drive pulley), 36... Rotor, 42... Recess, 43...
Sensor, 48...space. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] A sensor is provided around the crankshaft supported by the cylinder block to detect the crank angle through a rotor that rotates integrally with the crankshaft. A timing chain is provided to transmit the rotation of the shaft to the camshaft, and this timing chain is covered with a cover placed over the cylinder block, and at the shaft end of the crankshaft that protrudes outward through the cover,
In an engine equipped with a rotating body that rotates integrally with the crankshaft, the rotor and sensor are arranged in a space between the cover and the rotating body, and at least the above-mentioned sensor is placed on the surface of the cover facing the rotating body. An engine characterized in that a recess is formed to accommodate a sensor.