JPH01163457A - Choking detecting device for strainer element - Google Patents

Abstract

PURPOSE:To enable accurate reporting of choking of a strainer element to a user without being influenced by a pulsation pressure in an intake air passage, by a method wherein a pulsation damping pat is disposed to a communicating part between an actuating chamber and an intake air passage. CONSTITUTION:A choking detecting device 200 comprises an actuating chamber 320 positioned facing a follower chamber through a diaphragm 310, a diaphragm mechanism 300 having a follower chamber 330, a choking display mechanism 400 having a switch 420, and a pulsation damping part 500 located between an intake air passage 120 and the actuating chamber 320. An intake air negative pressure in the intake air passage 120 is introduced in a negative pressure chamber 513 through a negative pressure introduction hole 514. After a negative pressure in the negative pressure chamber 513 passes through a fine gap A between a surface 522 of a valve seat 520 and a surface 513 of a valve body 530, it is guided to the actuating chamber 320 through a hole 521 formed in the valve seat 520 and a negative pressure introduction port 351 in a regulating screw 350. A pulsation pressure is damped while it passes through the fine gap A between the surfaces 522 and 531.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for detecting clogging of a filter element that filters intake air of an internal combustion engine.

[Prior Art] Internal combustion engines used in automobiles, etc. are equipped with an air cleaner that purifies the air supplied to the combustion chamber in order to prevent minute dirt, dust, etc. from flowing into the combustion chamber along with the combustion air. ing.

When the filter element of this air cleaner becomes clogged with dust, the amount of combustion air supplied decreases, and the performance of the internal combustion engine deteriorates. Therefore, it is necessary to replace or clean the air filter element before it becomes clogged.

The timing of replacing or cleaning the filtration element is generally determined based on experience and usage time (mileage for cars), but experience cannot accurately judge the condition of the filtration element. However, since there is a significant difference in the internal combustion 81 flash usage environment when determining based on usage time, clogging could not be properly detected.

Therefore, as a technology to solve the above problems,
BACKGROUND ART A clogging detection device for an air cleaner (filtration element) disclosed in Japanese Utility Model Publication No. 36688 and Japanese Utility Model Publication No. 60-7296'1 is known.

Of the working chamber and the driven chamber, which are separated by a movable member such as a bellows or a diaphragm, these communicate the working chamber with the intake passage downstream of the air cleaner.
In order to display information to the user according to the moving position of the movable member, there is an electrical clogging display mechanism that uses a switch on the movable member, and a mechanical clogging display mechanism that links the movable member with an indicator such as a pointer. It used a display mechanism.

As the filtration element becomes clogged, the negative pressure in the intake passage increases and the pressure difference between the working chamber and the driven chamber increases, causing the movable member to move, causing the electrical clogging indicator to be activated. In the case of conventional filters, the switch was turned on and a lamp or buzzer alerted the user that the filtration element was clogged. Further, in those using a mechanical clogging display mechanism, the user is informed of the clogging state of the seven filter elements by the indicated value shown by the display.

[Problems to be Solved by the Invention] On the other hand, since there is pulsating pressure inside the intake passage due to intake pulsation, the negative pressure inside the intake passage fluctuates greatly depending on this pulsating pressure. (See Figure 3).

In the conventional system shown above, the negative pressure in the intake passage is directly guided to the working chamber! Because of the fA construction, the pressure inside the working chamber varied according to the pulsating pressure inside the intake passage, and the movable member also vibrated according to the pulsating pressure.

For this reason, as shown in Fig. 14, in devices that use an electrical clogging display mechanism, the switch repeatedly changes from 0N to OFF due to the pulsating pressure near the operating set value P2, so the power supply to the lamp and buzzer is interrupted. The voltage fluctuates, that is,
For example, lamps light up weakly at first, and light up more strongly as they become more clogged, making it difficult to determine when it is time to replace or clean the filter element.

In addition, in devices that use a mechanical clogging display mechanism, the display body vibrates in response to pulsating pressure, so the user must read the indicated value from the vibrating display body, making it difficult for the user to read the indicated value accurately. It was difficult to read the numbers.

Therefore, it is possible to interpose an orifice or nozzle between the intake passage and the working chamber to dampen the pulsating pressure, but the diameter of the orifice or nozzle must be extremely small, so diameter management is extremely difficult. It was difficult and had problems that made it impossible to put it into practical use.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a filter element that can accurately notify the user of clogging of the filter element without being affected by pulsating pressure in the intake passage. The present invention provides a clogging detection device.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes an operating chamber and a driven chamber that face each other with a movable member interposed therebetween, and which are interlocked with the movable member and arranged at the position of the movable member. The movable member is provided with a clogging display mechanism that displays corresponding information to the user, and the working chamber is communicated with the intake passage downstream of the filtration element of the air cleaner, and the pressure difference between the working chamber and the driven chamber causes the movable member to In the filtration element clogging detection device, the filtration element clogging detection device displays clogging of the filtration element to a user by the clogging display mechanism interlocked with the movable member. A pulsation damping section is disposed between the valve seat and the valve seat, the valve seat having a hole communicating the working chamber and the intake passage, and a valve body pressed against the valve seat so as to close the hole. The technical means is that the pulsating pressure is attenuated while the negative pressure in the intake passage is transmitted to the working chamber through a minute gap formed between the valve seat and the valve body.

[Function 1] The present invention having the above configuration has the following features:
A pulsation damping section is interposed in which the valve body is pressed against a valve seat having a hole that communicates the working chamber and the intake passage, and the hole is closed by the valve body. A minute gap is formed between the valve seat and the valve body. Therefore, the intake passage and the working chamber are communicated through a minute gap or hole.

The pulsating pressure in the intake passage is attenuated when passing through a minute gap, becomes static pressure, and is guided to the working chamber.

[Effect of the invention 1] According to the present invention, the negative pressure in the intake passage that fluctuates due to pulsating pressure is converted into static pressure by the pulsating damping section and guided to the working chamber, so that the movable member does not pulsate as in the conventional case. This prevents it from vibrating in response to pressure.

As a result, the movable member moves in accordance with the negative pressure in the intake passage converted to static pressure without being affected by the pulsating pressure in the intake passage. Clogging can be accurately notified.

Furthermore, since the pulsation damping section of the present invention damps pulsating pressure by the minute gap formed between the valve body and the valve seat, there is no need to manage the diameter like an orifice or nozzle.
As a result, it is possible to produce a single pulsation damping section that is small and has little variation in performance.

[Example] Next, a filter element clogging detection device of the present invention will be described based on an example shown in the drawings.

1 to 5 show a first embodiment of the present invention, and FIG. 1 is a filter element clogging detection device (hereinafter referred to as
FIG. 2 is a schematic cross-sectional view of an intake system of an internal combustion engine showing the installation state of the clogging detection device.

The internal combustion engine 100 for vehicle running has a combustion chamber (not shown).
Air cleaner 1 that purifies the combustion air supplied into the
10, and the combustion chamber and the downstream of the filtration element 111 that filters intake air in the air cleaner 110 are connected to the intake passage 12.
Contacted by 0.

A clogging detection device 120G is attached to this intake passage 120, which measures the negative pressure within the intake air R120 to detect clogging of the filter element 111.

This clogging detection device 200 includes a diaphragm machine l'1300 that includes an operating chamber 320 and a driven chamber 330 that face each other via a diaphragm 310 that is a movable member of the present invention, and a switch that is interlocked via the diaphragm 310 and an operating rod 410. an electrical clogging indicator mechanism 400 comprising 420;
It is composed of a pulsation damping section 500 interposed between the intake passage 120 and the working chamber 320.

The diaphragm mechanism 300 includes a diaphragm housing 340 that is a combination of a working chamber housing 341 that forms a working chamber 320 together with a diaphragm 310 and a driven chamber housing 342 that forms a driven chamber 330 together with the diaphragm 320. It is held between the chamber side housing 341 and the driven chamber side housing 342.

The working chamber side housing 341 is made of metal such as aluminum, and has a communication port 341 that connects the working chamber 320 with the outside.
a has been established. On the inner periphery of this communication port 341a,
A female thread 341b is provided. This female thread 341b
An adjustment screw 350 having a negative pressure introduction port 351 opened therein is screwed inside. This adjustment screw 350 is used to adjust the biasing force of a compression coil spring 360 that biases the switch 420, which is a normally closed contact, in the direction of opening via the diaphragm 310 and the actuating rod 410.

A spring receiver 311 that holds one end of the compression coil spring 360 and a retaining plate 312 that prevents the load of the compression coil spring 360 from being concentrated on the diaphragm 310 are attached to the diaphragm 310 by rivets 313. Furthermore, an O-ring 314 is disposed between the rivet 313 and the diaphragm 310 to maintain airtightness between the working chamber 320 and the driven chamber 330.

The driven chamber side housing 342 is made of resin, and has a sliding hole 342a for slidably holding the actuating rod 410 in the axial direction, and a communication hole 342b for communicating the inside of the driven chamber 330 with the outside. It has been established.

The working chamber side housing 341 and the driven chamber side housing 342 are fixed by a caulking part 341C provided at the end of the working chamber side housing 341, together with a resin switch case 421 in which a switch 420 is installed. ing.

A contact 422 and a contact spring 423 constituting the switch 420 are installed inside the switch case 421 , and the contact spring 423 is connected to the switch 42 by the actuating rod 410 .
0 is biased to open. The contact 422 and the contact spring 423 are connected to the outside of the switch case 421 via the terminal 424. Note that this terminal 424 is installed in the hole 421a for terminal assembly provided in the switch case 421 by caulking after Shintoism.
The inside communicates with the outside through the hole 421a. As a result, the driven chamber 330 communicates with the atmosphere through the communication hole 342b and the hole 421a.

The clogging display mechanism 400 displays information to the vehicle occupant according to the amount of movement of the diaphragm 310. In this embodiment, when the switch 420 is turned on due to the movement of the diaphragm 310, the clogging is within the visual range of the vehicle occupant. The provided clogging indicator lamp 440 lights up when the vehicle battery 450 is energized to indicate to the vehicle occupants that the filter element 111 is clogged. In addition, the reference numeral 4 shown in the figure
60 indicates a key switch.

The pulsation damping unit 500 includes a cylindrical valve case 510 having a male thread 511 formed on the outer periphery of one end and a female thread 512 formed on the inner periphery of the other end. Then, the female screw 512 is screwed into the male screw 341d provided on the outer periphery of the communication port 341a of the working chamber side housing 341. A cylindrical negative pressure chamber 513 is formed inside the valve case 510. and,
At the end of the male screw 511 side, the male screw 511 is attached to the intake passage 12.
A negative pressure introduction hole 514 is provided for guiding the negative pressure in the intake passage 120 into the negative pressure chamber 513 when screwed into the screw hole 121 of No. 0.

A valve seat 520 having a hole 521 that communicates the negative pressure chamber 513 and the communication port 341a is inserted into the end of the negative pressure chamber 513 on the side where the working chamber side housing 341 is installed from the female thread 512 side. There is. The periphery of the hole 521 on the negative pressure chamber 513 side of the valve seat 520 is a smooth surface 522, and a cylindrical flange 523 that is fitted into the valve case 510 is provided around the surface 522.

Further, inside the negative pressure chamber 513, a valve body 530 having a cylindrical diameter slightly smaller than the surface 522 is disposed. This valve body 5
i'1I1531 at one end of 30 is also provided smoothly. The surface 531 of the valve body 530 is pressed against the surface 522 of the valve seat 520 by the compression coil spring 540, and a small gap A is formed between the surface 522 and the surface 531.

In addition, the male screw 341d of the working chamber side housing 341,
When the female thread 512 of the valve case 510 is screwed together, an O-ring 550 is interposed therebetween. This 0-ring 5
50 provides an airtight seal between the male thread 341d and the female thread 512, and also seals the outer periphery of the valve seat 520 and the valve case 51.
In this embodiment, an O-ring 550 provides an airtight seal between the male thread 341d and the female thread 5.
12, and between the outer periphery of the valve seat 520 and the valve case 510.
However, the valve case 51G and the valve seat 520 may be sealed with an adhesive or a sealant, or the valve case 51G and the valve seat 520 may be fixed by driving, and the working chamber side housing 3
41 and the valve case 510 may also be sealed by being fixed by driving.

Next, the operation of the above embodiment will be explained.

When the internal combustion engine 100 operates, the combustion air filtered by the V filter element 111 of the air cleaner 110 flows into the intake passage 12 due to the valve opening action and intake action of the internal combustion engine 100.
0 into the combustion chamber. Due to this suction action, a pulsating intake negative pressure PO is generated in the intake passage 120, as shown in FIG.

This intake negative pressure PO is connected to a
It is guided into the negative pressure chamber 513 through the negative pressure introduction hole 514 of the pulsation damping section 500 of the clogging detection device 200. This negative pressure chamber 51
Similarly to FIG. 3, the negative pressure PO within the chamber 3 becomes a pulsating pressure and fluctuates greatly.

The negative pressure PO in the negative pressure chamber 513 is applied to the surface 52 of the valve seat 520 pressed by the compression coil spring 540.
2 and the surface 531 of the valve body 530, the hole 521 provided in the valve seat 520 and the adjusting screw 35
It is guided to the working chamber 320 through a negative pressure inlet 351 inside the chamber.

The pulsating pressure is attenuated while passing through the minute gap A between the surfaces 522 and 531, and is converted into static pressure as shown in FIG. 4 before passing through the hole 521 of the valve seat 520.

Therefore, since the negative pressure P1 converted into static pressure by the pulsation damping section 500 is introduced into the working chamber 320, the diaphragm 310
According to the pressure difference between the pressure and the atmospheric pressure introduced into the driven chamber 330, it is displaced without vibration, as in the conventional case.

When the filtration element 111 of the air cleaner 11G becomes clogged with dust or the like, the negative pressure within the intake passage 120 increases. The progress of clogging of this filter element 111,
In other words, as the negative pressure increases, the negative pressure p1 that is converted into static pressure by the pulsation damping section 500 and guided into the working chamber 320 increases, and the diaphragm 310 moves toward the working chamber 320. When the diaphragm 310 moves toward the working chamber 320, the switch 4 is moved via the working rod 41G according to the amount of movement.
20 contact springs 423 move toward the contacts 422. Then, the negative pressure P1 in the working chamber 320 becomes the working set pressure P
2 (see Figure 5), the contact 422 and contact spring 4
23 makes contact, and the switch 420 turns O as shown in FIG.
NL, the clogging indicator lamp 440 is the in-vehicle battery 450
is energized and lights up. As a result, the vehicle occupant can see the filtration element 11 due to the lighting of the clogging indicator lamp 440.
1. Know when it is time to replace or clean.

Note that the operating set pressure P2 is determined by the compression coil spring 360.
It is set by the spring constant of , and the screwing amount of the adjustment screw 350.

As shown in the above embodiment, the clogging detection device 200 to which the present invention is applied has a pulsation damping section 500 in the working chamber 320.
Since the negative pressure P1 converted into static pressure is introduced, the diaphragm 310 (movable member) is prevented from vibrating in response to pulsating pressure, as in the conventional case.

As a result, the diaphragm 310 maintains the negative pressure P1 converted into static pressure without being affected by the pulsating pressure within the intake passage 120.
Therefore, the clogging display mechanism 400 can accurately notify the user of the clogging of the filtration filter 111.

Further, the pulsation damping section 500 shown in this embodiment has a valve seat 5
Because it is a mechanism that attenuates pulsating pressure by the minute gap A formed between 2G and the valve body 530 and converts it into static pressure, it is similar to orifices and nozzles that are conventionally known for attenuating pulsating pressure. There is no need to manage the diameter, and as a result, it is possible to mass-produce the pulsation damping section 500 which is small and has little variation in performance.

A second embodiment of the present invention is shown in FIGS. 6 and 7.

In this embodiment, the surface 531 of the valve body 530 of the pulsation damping section 500
A ring-shaped protrusion 532 surrounding the hole 521 of the valve seat 520 is provided. As a result, the valve seat 52
0 and the valve body 530 can be improved,
Variations in the performance of the pulsation damping section 500 can be further reduced.

FIG. 8 shows a third embodiment of the present invention.

In this embodiment, the surface 531 of the valve body 530 is provided in a conical shape, and the surface 522 of the valve seat 520 is also provided in an inner bowl shape corresponding to the surface 531.

FIG. 9 shows a fourth embodiment of the present invention.

In this embodiment, the valve body 53G is provided in a spherical shape, and the surface 522 of the valve seat 520 is curved so that the valve body 520 is guided into the hole 521.

FIG. 10 shows a fifth embodiment of the present invention.

In this embodiment, the valve body 530 itself is provided with a leaf spring, and the valve body 530 is pressed against the valve seat 520 by the biasing force of the leaf spring, thereby closing the hole 521.

11 and 12 show a sixth embodiment and a seventh embodiment of the present invention.

In this embodiment, the valve body 530 itself is made of hard rubber, and the valve body 530 is pressed against the valve seat 520 by the urging force of the hard rubber, thereby closing the hole 521.

FIG. 13 shows an eighth embodiment of the present invention.

The biasing means of the above embodiment pressed the valve body 530 against the valve seat 520 against the negative pressure, but as shown in this embodiment, the spring constant of the compression coil spring 540 is set lower than that of the above embodiment, Even if the valve body 530 is pressed in the direction of suction by negative pressure, the pulsating pressure can be attenuated by the minute gap A formed between the valve body 530 and the valve seat 520.

In this embodiment, the negative pressure introduction hole 514 that communicates the intake passage 120 and the negative pressure chamber 513 is the hole of the present invention, and the wall surface 515 forming the hole is the valve seat of the present invention.

(Modification) In the above embodiment, the movable member is provided with a diaphragm, but a movable member with other partition walls such as bellows may be used.

In addition, an example was shown in which a lamp is lit on the clogging display mechanism to notify the user when it is time to replace or clean the filter element, but a buzzer may also be used to notify the user.
A variable resistor may be interlocked with the movable member to display a numerical value to the user according to the position of the movable member.Also, a display body such as a pointer may be provided on the movable member, and the value indicated by the display body may be provided. It may be provided to indicate to the user the state of clogging of the filter element.

[Brief explanation of the drawing]

Figures 1 to 5 show a first embodiment of the present invention, in which Figure 1 is a schematic sectional view of a clogging detection device for a filter element, and Figure 2 shows how the clogging detection device is installed. Figure 3 is a graph showing fluctuations in negative pressure due to pulsating pressure; Figure 4 is a graph showing negative pressure converted to static pressure by the pulsation damping section; Figure 5 is a schematic cross-sectional view of the intake system of an internal combustion engine. 6 is a graph showing the relationship between the negative pressure introduced into the working chamber and the switch, and FIG. 6 is a cross-sectional view of the main part of the clogging detection device for the transient element of the second embodiment.
FIG. 7 is a sectional view of the valve body, FIG. 8 is a sectional view of the pulsation damping part showing the third embodiment, FIG. 9 is a sectional view of the pulsation damping part showing the fourth embodiment, and FIG. FIG. 11 is a sectional view of the pulsation damping section showing the fifth embodiment, FIG. 11 is a sectional view of the pulsation damping section showing the sixth embodiment, FIG. 12 is a sectional view of the pulsation damping section showing the seventh embodiment, and FIG. FIG. 14 is a cross-sectional view of the pulsation damping section showing the eighth embodiment, and is a graph showing the relationship between the negative pressure introduced into the working chamber of the conventional clogging detection device and the switch. In the figure 100... Internal combustion engine 110... Air cleaner 111... Filtration element 120... Intake path
200... Clogging detection device 310... Diaphragm (movable member) 320... Working chamber 330... Driven chamber 400... Clogging display mechanism 500... Pulsation damping section 520... Valve seat 521...hole 530...
Valve body 540... Compression coil spring (biasing means)
A...Minute gap Fig. 3 Fig. 4 Fig. 5 Negative pressure Fig. 14 B2 Negative pressure - Fig. 10

Claims (1)

[Scope of Claims] The device includes an operating chamber and a driven chamber that face each other via a movable member, and also includes a clogging display mechanism that works in conjunction with the movable member and displays information to the user according to the position of the movable member. , the working chamber is communicated with an intake passage downstream of a filtration element of the air cleaner, the movable member is moved by a pressure difference between the working chamber and the driven chamber, and the clogging indicating mechanism is interlocked with the movable member. In the clogging detection device for a filtration element, which displays the clogging of the filtration element to a user by means of A pulsation damping section is provided that includes a valve seat with a communicating hole and a valve body pressed against the valve seat so as to close the hole, and the negative pressure in the intake passage is applied between the valve seat and the valve body. A clogging detection device for a filtration element, characterized in that pulsating pressure is attenuated while being transmitted to the working chamber via a minute gap formed between the filtration element and the valve body.