Snow removing machine

Abstract

To solve the problem that working interruption trouble such as engine down due to overload of an auger or sudden stoppage while the engine is operated frequently occurs due to various changes in snow-removing conditions such as hardness or softness of snow quality, heavy or light weight, and difference in the state of each layer of accumulated snow during the progress of snow removal.SOLUTION: By a control unit capable of vertically moving the snow-removing part up and down with respect to the traveling direction of the machine body, the snow-removing part is vertically oscillated at a set frequency and at a set oscillation angle, so that a completely new "oscillating snow-removing system" which prevents a snow-removing interruption trouble is developed.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a small walk-behind snow removal machine that is primarily used by individuals, farms, stores, offices, small and medium-sized businesses, etc., and relates to improving the snow removal work efficiency and maneuverability of the machine. [Background technology]

[0002] Small walk-behind snowplows are now widely used in snowy regions for individual small-lot applications, separate from the large snowplows used on nationally and prefecturally managed public roads and facilities. Demand is particularly high in mountainous and foothill areas, where large snowplows cannot enter, making them a necessity in snowy regions. As they have become more widespread, safety features have been developed to prevent numerous injuries and operational problems. This application relates to the operational assistance features, and addresses further advances in this technology. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6307731 Summary of the Invention [Problem to be solved by the invention]

[0004] Snow removal with a snowplow is typically performed in urban areas where snow accumulation is relatively low (below the snow removal unit height), but most snow removal requires driving on snow several meters deep. Naturally, snow removal is performed in stages, starting from the top and working your way down (road surface, ground) (step snow removal, top diagram in Figure 8). This is also true for large snowplows; when roads are cleared without clearing the entire surface, snow walls remain along the roadside. Snow removal on mountain roads in tourist areas can reach several meters, with the largest being the "Snow Valley" (over 20 meters) on the Kurobe Alpine Route, which remains a snow corridor and a tourist attraction until early summer. Unlike stable road driving, even crawler snowplows can encounter endless problems when driving on snow, such as tilting left and right, lifting up and down, sinking, falling into depressions, and encountering obstacles in the snow. Regarding the vehicle's attitude, horizontal control has long been used to correct for tilting left and right. The applicant previously developed this technology and developed a pitching attitude correction control technology that corrects problems in the fore-and-aft direction of the aircraft, i.e., lifting and sinking, and prevents climbing up and falling down (Patent Document 1).

[0005] However, apart from the driving posture issues that lead to operational interruptions due to irregular snow surfaces, there are also several other issues that affect snow removal efficiency itself, which have yet to be resolved. Among these, sudden stops during forward movement or engine shutdowns due to overload frequently occur. The causes depend not only on the type of snow (hard or soft, heavy or light), but also on the condition of each layer of snow. For example, the bottom layer of snow may be hard, causing the blade or sled at the bottom of the auger case to hit the snow, resulting in a stoppage. The industry has traditionally instructed users on how to handle these issues, such as "intermittent snow removal" or "forward and reverse snow removal" (bottom center of Figure 8). However, these issues can also be considered operational interruptions. While some experienced operators may adjust the height of the blade or sled to suit their own operation, they do not always adjust for all operating conditions. However, we have long noted that among experienced operators, there are a very limited number with extensive work experience who can work continuously without interruption, even in difficult conditions. This application aims to incorporate the operating know-how of highly skilled operators into the snow removal machine control elements, preventing factors that would cause even beginners or inexperienced operators to stop work and allowing continuous snow removal work to be continued, thereby significantly improving work efficiency and further preventing accidents. [Means for solving the problem]

[0006] The means adopted in this invention to solve the above problems is a snow removal machine equipped with a prime mover and comprising a snow removal section consisting of an auger that scrapes, crushes, transports and collects snow, a blower that discharges the collected snow, and a chute that determines the direction of snow throwing. The snow removal section is driven by an actuator so that it can be raised and lowered up and down in the direction of the machine's travel. In this snow removal machine, an inclination sensor is disposed in either the snow removal section or the machine that moves up and down together with the snow removal section in a direction that detects the elevation angle of the snow removal section, and the snow removal section is moved up and down by the actuator. This snow blower is designed to automatically adjust the front and rear tilt angles relative to the machine's forward direction to a tilt angle set by a control unit. When the engine speed drops below a set value due to overload while the machine is moving forward, or when a sudden drop in speed causes the machine to come to a halt, or when the automatic adjustment of the front and rear tilt angles becomes ineffective, the control unit causes the snow blower to swing up and down starting from the rising side at a set frequency and with a set swing angle, resulting in the development of a completely new and unprecedented "swinging snow removal method." [Effects of the Invention]

[0007] By implementing the above means, the present invention has the following effects.

[0008] This system allows for stable, continuous snow removal without interruption, regardless of the snow accumulation conditions or driving conditions, dramatically improving snow removal efficiency.

[0009] Work interruption troubles are significantly reduced, which helps prevent accidents and improves safety. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is an overall view showing a walk-behind rotary snow blower. [Figure 2] 1 is a diagram showing the operation of the snow blower. FIG. [Figure 3] FIG. 4 is a side view showing the snow removal unit swing control operation mechanism. [Figure 4] FIG. 10 is a diagram showing the installation of a tilt sensor on an auger housing. [Figure 5] FIG. 10 is an image diagram showing the up and down swinging motion of the auger. [Figure 6] FIG. 4 is a diagram illustrating engine speed detection and speed detection. [Figure 7] This is a diagram summarizing the effects of the rocking snow removal method. [Figure 8] This is an image diagram showing snow removal methods such as step snow removal, intermittent snow removal, and forward and backward snow removal. [Figure 9] 10A and 10B are diagrams illustrating the control of the snow removal unit swing in the compact machine embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] This invention was born from a completely new idea that had never been seen before, and although there was no data to refer to, we learned from the principle of swing cutting in machining technology and set the swing cycle of the snow removal unit to be close to the auger rotation speed. This is thought to maximize the swing snow removal effect. [Example]

[0012] An embodiment of the present invention will be described with reference to the accompanying drawings. Figure 1 shows a perspective view and a front view of a snow removal machine of the first embodiment, viewed from the snow removal unit 1 side. A snow removal machine typically uses an auger 11 to scrape and break up accumulated snow, while simultaneously transporting and collecting it in the center using a spiral conveyor. The blower (not shown) located at the rear of the center of the auger 11 rotates at high speed, and discharges the snow using the blower's rotational speed and compression, and the snow is then thrown by a chute 2 to the operator's intended location. Figure 2 shows the operation as viewed from the control panel side. When the snow removal unit 1 is manually operated, the lift position and left / right rolling positions are controlled using the snow removal unit cross lever switch 61 on the control panel 6. Similarly, the left / right direction and the distance of the snow throw are controlled using the chute cross lever switch 62. The auger, blower, and chute are mounted on the upper machine body 4 along with other control components and a motor (not shown). The crawler 3 and traveling transmission 51, which move the snow removal machine, are mounted on the lower machine body 5.

[0013] Figure 3 shows the lifting and lowering control operation of the snow removal unit 1. A snow removal unit lifting cylinder H1 is journaled between an upper frame 41 that supports the entire upper body 4, including the snow removal unit 1, and a lower frame (not shown) that supports the lower body 5, which constitutes the traveling section. The extension and retraction of this cylinder causes the entire upper body 4, including the snow removal unit 1, to rotate up and down around the axis of the drive sprocket of the crawler 51, on the opposite side of the upper frame 41 from the side that supports the snow removal unit 1. The upper diagram shows the upper body in a nearly horizontal position, while the lower diagram shows the snow removal unit lifting cylinder H1 extended and raised. When the snow removal unit lifting cylinder H1 was first introduced, a hydraulic single-acting cylinder was sometimes used. However, due to the importance of the step-cut snow removal function (top diagram of Figure 8), a more aggressive push-down below horizontal is required. Therefore, a double-acting cylinder, which the applicant first adopted in the industry, is now almost always used. In other words, when the snow removal unit 1 is lowered below horizontal on the road surface, the blade plate 121 under the auger case 12 hits the road surface, causing the front of the machine to rise accordingly. This is the general configuration of the walk-behind snow removal machines (medium and large models) that are currently in widespread use.

[0014] Figure 4 shows the installation state of the snow removal unit tilt sensor S1, which detects the elevation angle of the snow removal unit 1. A bracket is fixed horizontally to the back side of the auger case 12, and the tilt sensor S1 is bolted to that horizontal surface. The bracket also mounts the motor and gear reducer that rotates the chute 2.

[0015] The hydraulic solenoid unit that operates the hydraulic cylinder (actuator) is a spring-center type with a sliding spool-type electromagnetic solenoid, the most basic type found in common four-way selector valves. Two of the four ports operate the lift cylinder H1, and the other two operate the rolling cylinder (not shown) that rotates the snow removal unit 1 left and right. Currently, a cross-lever switch 61 is typically used to manually switch between these four hydraulic circuit directions. A hydraulic solenoid valve outputs from only one of the four ports; it cannot simultaneously output from multiple ports. However, the applicant has previously achieved simultaneous control of two hydraulic control systems, lift control and rolling control of the snow removal unit 1, using a single hydraulic control system through time-sharing alternating control within the hydraulic response range (approximately 100 ms or less) (Patent Document 1). This technology is only possible with an extremely slow-speed snow removal machine.

[0016] The swing snow removal control of the present invention is explained in Figure 5. This control system was originally developed to prevent the vehicle from accidentally lifting up or sinking into the snow during snow removal due to irregular conditions on the snow removal surface, resulting in an abnormal posture and requiring the vehicle to move backward to clear the snow again (forward / reverse snow removal), or becoming unable to escape, resulting in significant interruptions to the operation. When the output value of the inclination sensor S1 attached to the snow removal unit 1 exceeded a preset reference inclination angle, the control unit U1 operated the solenoid valve to bring the inclination angle of the snow removal unit 1 within the reference inclination angle, operated the lift cylinder H1, and raised and lowered the snow removal unit 1. The crawler 3 of the running unit then climbed up and advanced on the snow removal surface cleared to the reference inclination angle, returning the vehicle to the preset inclination posture, and the snow removal unit 1 also returned to that inclination position, thus correcting the vehicle's posture (top diagram) (Patent Document 1). While this invention seemed to have largely solved the problem of work interruptions during snow removal, there were still some troublesome issues that remained, as mentioned above.

[0017] The control system for the snow removal unit 1's oscillation is the same as before, except for the tilt sensor. The oscillation angle is set to approximately 2° (±1°) to 6° (±3°), and the oscillation cycle is set to approximately 3 Hz. The oscillation cycle needs to be synchronized with the rotation of the auger 11, but the auger 11's rotation speed is low, at approximately 188 rpm (3 Hz), making it easy to synchronize and well within the response range of the hydraulic control system, allowing for a comfortable setting. However, this was fortunate, as the auger 11's rotation speed was not particularly high. This and the preceding attitude correction control are prioritized and controlled simultaneously. However, because abnormal behavior such as hunting occurred during oscillation, the tilt sensor was changed from the conventional liquid level capacitance type to a type that is not affected by vibration, using digital filtering to remove the influence of vibration from the MEMS sensor output. This was also developed by the applicant for a separate project.

[0018] The idea behind the swinging action of the snow removal unit 1 came from the observations of the highly skilled worker mentioned above. One example is when the snow removal unit suddenly stopped during snow removal. Normally, the operator would step back and start again, but by operating the snow removal unit cross lever 61 and HST lever 63, the snow removal unit could be restarted without any problems. The stoppage occurred because the blade plate 121 under the auger case 12 hit a hard layer of snow underneath, which is a common problem that causes the auger and crawler to spin freely. In fact, there are cases where the snow removal unit gets caught between the snow walls on both sides of the snow that has been removed, and the lateral pressure causes the snow removal unit to stop. Although the auger rotary blade scrapes off the snow and the crawler travels, the road surface has a much lower μ than it appears, and once it starts to slide, it has traditionally been the norm to stop and start again. Also, when the engine is about to stall due to hard or heavy snow during snow removal, Small machines will simply shut down, but powerful medium- to large-sized machines will use the remaining power from the torque reaction of the auger 11 to climb up onto the pile of snow to avoid the overload, and mysteriously, the machine will always act as if it is trying to reduce the snow removal load itself. When this happens, it will not be able to continue working, so it will drop back down once, move back a little, then regain its balance and start removing snow again (reverse snow removal, Figure 8, bottom). This has traditionally been the common sense, and the industry has also been teaching it in this way.

[0019] An experienced operator operates the snow blower with only a slight up-and-down movement, using the cross lever 61 to lift the snow blower unit 1 slightly (to avoid the hard snow layer) and then quickly return it to its original height. However, this operation would not work properly for an unskilled operator. It would also not work if the operator stopped the machine completely and started spinning. The operator's intuitive response plays a major role. An experienced operator can detect the snow blower's impact before it completely hits the hard snow layer by detecting the sound of the auger rotating, the engine, and the change in snow blower load resistance sensed through the control lever, and then operate the machine just before it hits the hard snow layer. An unskilled operator does not have this kind of physical sense. Operating a snow blower requires constant control of the snow blowing load, so the operator often has to grip the HST lever 63, which adjusts the driving speed, and the snow blower cross lever switch 61, which adjusts the height and rolling position of the snow blower unit 1. Furthermore, the snow throwing position is controlled by the chute cross lever switch 62. Operating these functions simultaneously requires more than just average motor skills and requires proficiency. Furthermore, beginners, elderly people, and women often hold the handlebars at 65 degrees to maintain a stable riding position, making this an impossible task.

[0020] This slight up-and-down movement was not only performed at the time, but also occasionally before and after. It sensed changes in the snow removal load resistance and rolling resistance. This was the difference between an expert and a super-expert. Each small up-and-down movement allowed the snow removal machine to continue working smoothly and without interruption. The term "swinging" (or "waving") was coined to describe this newly developed snow removal method, and it ushered in a new era. Many industrial technologies use swinging, including swinging cutting, swinging transport, swinging sorting, swinging cleaning, and swinging excavation. The number of swinging cycles was determined based on the swinging cutting principle. It was discovered that the swinging snow removal method has many benefits beyond its original purpose of preventing driving stops and work interruptions due to adverse conditions. By automatically performing the swinging operation, or slight up-and-down movements of an experienced operator, in response to changing snow removal conditions, the snow removal machine can proactively adapt to changing snow accumulation conditions.

[0021] A completely separate issue from the present application, one of the benefits of oscillating snow removal is the problem of snow clogging in Chute 2 (which requires a complete shutdown and requires several tens of minutes or more until snow removal can be restarted). The operator had long known that this rarely occurred, but this was due to the oscillating snow removal method. Regarding snow clogging in the chute, a technology to prevent snow clogging was previously developed for use in the early snowfall season (Snow Block) (Patent No. 6853448). This was primarily a solution for fresh snow that adheres to the soles of skis and snowboards, and was essentially a strip of wax to prevent snow from adhering. In contrast, with the high moisture content of early spring snow, the snow flakes that were carefully scraped and removed by the auger can compress and resolidify during transport, overloading the blower's discharge force and causing snow clogging. Oscillating transport prevents this, preventing snow clogging in the blower-chute. At the same time, the oscillating snow throw also effectively prevents snow from adhering to the chute. It also served as a snow clogging prevention measure throughout the snow removal season. Furthermore, based on the principle of oscillating cutting in machining technology, if the oscillation cycle is synchronized with the rotation of the auger 11, snow-cutting ability will also improve. Without even realizing it, the snow-cutting ability had improved. However, this can only be understood by physical experience.

[0022] Figure 7 shows the effect of rocking snow removal. Snow removal using an auger is rocking snow removal, while transport using a spiral conveyor is rocking transport. Rocking snow removal is associated with rock cutting in machining, but from actual observation, it is similar to rock excavation and rock cutting in civil engineering. The rocking transport and collection process also showed a clear difference in density with and without rocking motion. The operator's own feeling was that there was almost no sense of jamming as the snow removal tool moved forward, and it felt as if the snow-cutting performance, or snow removal ability, had been improved (middle and bottom rows of Figure 5). This tactile sensation (tactile effect) is invaluable for snow removal machines and other implements. Rather than theory or numbers, the best way to convince users is to let them understand the effect immediately by using it.

[0023] Figure 6 shows the mechanisms for detecting engine rpm and vehicle speed. Engine rpm is detected from the rectifier of the generator module, an engine accessory. Vehicle speed pickup detection was developed prior to this application (Patent No. 6719700). Due to the low magnification of snow removal speed and track speed versus track wheel rotation, it is sufficient to detect one pulse per rotation of the crawler driven wheel (track wheel). Even with a simple pickup detection mechanism, it is stable, making it suitable for snow removal environments and enabling detection of the crawler moving parts in harsh environmental conditions.

[0024] However, this swinging snow removal is most effective in the latter half of the snow season, and is not so necessary in the early snowfall period, when the snow is just starting to fall, and is in fact rather a nuisance, so for the time being, we have decided to operate the function on and off with a switch from the beginning of the snowfall. During the early snowfall period, in order to secure living areas, workers often have to work desperately to remove snow even in the middle of the day, even though it is snowing heavily, so we cannot afford to surprise workers with unconventional operations. From the maintenance of living areas by additional snow removal in the middle half to the complete snow removal to expand living areas in the latter half, work is carried out on relatively good weather in order to increase efficiency, and this is where this control comes in.

[0025] Figure 9 shows a second example for a small-sized machine. The tilt sensor and control unit are located in similar positions. The snow removal unit lift cylinder H1 uses an electric hydraulic cylinder, and only the snow removal unit 1 is raised and lowered using a link mechanism. Separate left and right cylinders (not shown) are also provided, and are manually operated using the snow removal unit cross lever switch 61, just like medium- and large-sized machines. Among current small-sized machines, only the top-of-the-line models use actuators to operate the snow removal unit. Small-sized machines are only capable of driving on the road surface and clearing snow there at best, and are almost completely unable to drive on snow and perform full-scale step-clearing. Therefore, the pitching attitude correction control previously used was not implemented, but because the effect of swing snow removal control was so great that it was noticeable to the naked eye, it was decided to install it in the small-sized, high-end models as well.

[0026] As described above, we have developed a swinging snow removal system and its usage, the "swinging snow removal method." While it does not achieve the same level of skill as a highly skilled operator, by coming somewhat close to that level, we have made it possible for anyone to operate the system with ease, which will contribute to improving life in snowy regions and preventing snow removal accidents. [Industrial Applicability]

[0027] In similar fields, agricultural machinery such as combine harvesters and hullers use rocking sorting, while other machining fields use rocking cutting and rocking cleaning. Furthermore, in other fields such as semiconductor manufacturing, the chemical industry, pharmaceutical manufacturing, and civil engineering, rocking motion has already been used in many fields to improve performance and has become a well-known industrial technology. Looking back, the use of the snow removal machine of the present application in a snow removal method, albeit only just now, can also be used in all other fields that were previously unrelated to the snow removal machine. [Explanation of symbols]

[0028] 1 Snow Removal Department 2 Shooter 3. Crawler 4 Upper fuselage 5 Lower fuselage 6 Control Panel 11 Ogre 12 Auger Case 121 Blade 122 Sled 41 Upper frame 51 Driving Mission 52 HST 53 HST trunnion axis rotation motor 61 Snow removal unit cross lever switch 62 Shooter Cross Lever Switch 63 HST lever 64 Monitor & Switch Operation Panel 65 Control Handle 641 Snow removal unit swing control switch 642 Automatic pitching control switch S1 Snow removal unit tilt sensor H1 Snow removal section lifting cylinder U1 Pitching / Swinging / Automatic Control Unit

Claims

1. This snow removal machine is equipped with a prime mover and has a snow removal section consisting of an auger that scrapes and collects snow, a blower that ejects snow, and a chute that determines the direction of throwing the snow. The snow removal section is driven by an actuator so that it can be raised and lowered up and down in the direction of the machine's travel. A tilt sensor is disposed in either the snow removal section or the machine, which moves up and down simultaneously with the snow removal section, in a direction that detects the snow removal section lift angle. The actuator automatically adjusts the front and rear tilt angle of the snow removal section in the direction of the machine's travel to a tilt angle set by a control unit. The control unit swings the snow removal section up and down at a set frequency and swing angle, causing the auger to swing and scrape the snow. The shaved snow flakes are swing-transported and collected by the swinging rotation of the auger spiral conveyor, and are then swing-thrown down the chute to remove the snow (swinging snow removal system).

2. 2. A snow removal machine (swinging snow removal system) as described in claim 1, wherein the snow removal unit is configured to perform the swinging operation starting from the rising side when the engine speed drops due to overload during forward snow removal operation, when the forward movement is about to stop due to a sudden deceleration, or when the automatic adjustment of the front and rear tilt angle position relative to the vehicle's forward movement direction becomes ineffective.

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